How to Detect Low AC pressure Easily Ie F250 or F350
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- Опубликовано: 2 апр 2020
- Don't have the equipment to check, no problem, here's a quicky vid on how to check for low refrigerant in your truck or car. There are a lot of things in an AC systems that can cause it to work improperly, but LOW refrigerant is the most common. It’s, & USUALLY the easiest to fix, even for the common person. This video is a quick guide and is NOT intended to cover EVERY possible problem. It's the quick & dirty check for the average person who doesn't have hundreds of dollars of equipment. The major cause of Low Refrigerant is a slow leak. ALL systems leak a little but over time they should last for 5-10 years before it leaks down enough to cause problems. "IF" the system has NOT been opened, lines disconnected, you can most of the time use a quick charge kit and you’re good to go. “IF” you opened the system, lines disconnected, you''ll most likely have to pull a vacuum on it AFTER you replace the seals, and Dryer/Accumulator. After repairs, make sure and do a good inspection on the lines and joints where the system connects together. You'll want to look for a dark oily area covered with dirt, or an area that is bright green. If you find such an area, change the seal or that component. The Condenser behind the grill if it gets hit with a large sharp rock can easily be punctured and you'll see that dark dusty oily area where the seal was broken and the refrigerant leaked out. Anyways do your homework BEFORE removing any parts. YOU CAN RENT vacuum pump and an AC gauge set to do the job correctly. Some Automotive stores like AutoZone will rent them for FREE!. You put down a deposit on the equipment and when you bring it back you get ALL of our deposit back! If you open a system replace the dryer/accumulator to be safe, as a minimum. If you just opened it for part of the day and you have already replaced it, you can just pull a vacuum and it should be good. Hope this helps point you all in the right direction. If you learned something please give the video a thumbs up and if you would like to help my channel, please subscribe.
* On a side note. Go check out the comments for Mike Smith below. Some GOOD info there as well.
** I'm working on a series on how to completely rebuild the AC system by replacing EVERY item in the engine bay related to the AC System. I shot the videos already, I just need to edit them!
*** I'll show how to:
- Replace ALL the components under the hood.
- Find & test for leaks.
- Pull a vacuum.
- Recharge it.
- List ALL the Part Numbers.
- Where to find the parts cheap and get access to the tools WITHOUT BUYING THEM!
Thanks for watching and glad to help. Best Wishes & Blessings. Keith Noneya 
Авто/Мото
Best video on 7.3 a/c explained I have found . Thanks man middle of July in Texas 109 temp . A/c is necessary.
Thanks Scroungy. Oddly it's one of my best video's that I just slapped together for a friend who was having AC problems. Thanks for watching. Best Wishes & Blessings. Keith Noneya
Thank you for this one! Worked like a charm after I tried for half an hour to get the system to charge. Great video!
Ah glad to help Eric. I just threw this one together as a quickly for a friend who was having problems with his AC. Another thing when having problems charging a system if it won't charge don't over look the coupler valves on the ends of the AC Gauge set. I had a Low Pressure Coupler that was clogged and I had a heck of a time figuring it out. After I figured it out everything went smoothly and I was able to charge my system quickly. Thanks for watching. Best Wishes & Blessings. Keith Noneya
This video was exactly what I was looking for. God bless you brother!
Awesome glad you liked it. It doesn't cover everything but it can get you in the ball park and save you some cash. Don't forget to check out the comments there's some good ones in there that can help even more. Thanks for watching. Best Wishes & Blessings. Keith Noneya
Thanks ! This helped with my 04 F250.....
Glad it helped! That's why I make these video. Not everyone can afford to pay the $300.00 to $1,200.00 repair bill on this. Thanks for the thanks, much appreciated. Best Wishes & Blessings. Keith Noneya
I'll check it out thanks. You're overdue for a new belt !
Hey RC, thanks hope it works well for ya. Best Wishes & Blessings. Keith Noneya
Excellent AC video
Glad you enjoyed it, I hope it helped. Thanks for watching. Best Wishes & Blessings. Keith Noneya
That's exactly what is happening in my truck! Following your explanation, it's low in pressure, thanks man!
Cool. Glad to help. Best Wishes & Blessings. Keith Noneya
Very informative, thanks for sharing
Glad it was helpful! Best Wishes & Blessings. Keith Noneya
Thank you Keith! I appreciate it👍🏻🙏🏻
Anytime Bud! Keith
Very helpful! Thank you!!!!
Glad it was helpful! Thanks for the comment. If you need anything else let me know. Best Wishes & Blessings. Keith Noneya
Thanks, Keith!
You're welcome Roberto, hope it helped. Best Wishes & Blessings. Keith Noneya
I will try this tomorrow. But all in all looks to be A really good video
Thanks it's not all encompassing but it covers a lot of the basics. If you need any help just drop a comment and when I see it I'll try and answer your question or give you some ideas where to find it. Thanks for watching. Best Wishes & Blessings. Keith Noneya
You have one of the best informative videos on this topic I've saw! I have a 05 4.6 and replaced the compressor thinking it was bad, well come to find out the old one was good afterall. However my ac compressor clutch isn't kicking in. Was told the pressure switch could be the problem. So hopefully that's it. Fuse is good so I'm not sure where else to look after I swap the pressure switch.
There's a Orifice tube that regulates the vapor going into the Evaporator, (a small Aluminum Radiator). The Evaporator is in the clam shell housing on the left side in the engine bay Those Evaporators get clogged externally with dust and debris. Here's a video on how to clean it: ruclips.net/video/TqFf7tP7Nfw/видео.html. - The video is from another channel but it's a pretty good one.
Sorry I don't have a video on the orifice tube but the Orifice Tube can be pulled and you can clean it or replace it. . But you have to vent all the R134A out to do it, then recharge the whole system again. A local AC shop can evacuate the R134A for you and if you rent the vacuum pump and gauges you can then recharge it.
Hope that points you in the right direction. Feel free to ask more questions. I've rebuilt mine and have done others so its no problem to answer most of your questions. Best Wishes & Blessings. Keith Noneya
Great stuff sir, having ac issues myself. I'm gonna check it out tomorrow great video very informative.
No problem glad to help. Let me know if you need anymore help. Just ask away, that's what my channel is about. Also do me a favor and give the video a thumbs up, if you haven't already and subscribe,, even if you don't come back it helps my channel.
In the future I'm going to do a complete series on how to rebuild the AC system by replacing EVERY item in the engine bay related to the AC System.
- I'll show how to find test and find leaks
- Pull a vacuum
- Recharge it.
- Where to find the parts cheap and get access to the tools WITHOUT BUYING THEM!
Thanks for watching and glad to help. Best Wishes & Blessings. Keith Noneya
@@keithnoneya I bought a can of the ac recharge stuff but I don't think my compressor is working
Mike Smith and I live in the same town. We met up at his house and found he had in intermittent High Pressure Switch (HPS), the one next to the compressor. I wiggled the connector on it and it cut in and out. We thought it was the wires but when I put my old HPS on his connector the compressor fired right up. Next I wiggled the wires again and it kept running. That meant the pin contacts in HPS on his truck was intermittent. We changed his HPS with my old one, lost a little R134A because the shrader valve in the line was stuck open, after that it ran great with no intermittent problems. We also had to change the seal while it was venting R134A, not fun. I just put it on slowly and I used my fingernail to keep the seal pushed up into the HPS. I snugged it up and used 50% dish soap & water and leak checked it. It seal, thank the Lord! We put about a 18oz in it and his AC is running and cooling great now. Thanks Mike for letting me come over and hang with you, your fine truck, & family. Best Wishes & Blessing. Keith Noneya
@@keithnoneyawhat the name of that valve on the tank that plugs in on the tank in the fire wall
@@yashuwasaves Schrader Valve. It's what holds the R134A in the system if you remove the Cycle Switch to replace it. The Cycle Switch is what the connector plug connects to on the cylinder (Accumulator Dryer) on the firewall. If you change the valve make sure it's an AC Schrader valve not one for a car tire. I hope that answers your question. Best Wishes & Blessings. Keith Noneya
Man you really helped thanks
No problem Steve, let me know if you need anything else. Best Wishes & Blessings. Keith Noneya
Thank you, well you done
Thank you I appreciate it. Glad to help. Best Wishes & Blessings. Keith Noneya
3Pin: Do you have any information on the Ford HVAC low pressure 3 pin switch?
Hey man, change your serpentine belt 🤣 , its hanging on by a thread .
LOL, I actually did last week. It finally went after two years of running like that. I should be making a video on just that subject in a month or so. I also just did a video on the Belt Tensioner and posted it early this morning. Thanks for the comment I hope the video was helpful. Best Wishes & Blessings. Keith Noneya
Great video! I have a late 99 F-350 and my compressor clutch cycles on and off all the time, but the A/C blows nice and cold. Should I leave it alone or should I dig into it and see if I could fix it? I could do the trick with the paper clip and add 134A if it's reading low, but I don't have any gauges to check the high side and I just don't want to damage something that is working. Well its cooling at least.
AC compressors are designed to go on and off. It's the main reason the Low Pressure Switch's real name is the Cycle Switch. The system is designed to build pressure then turn off and let the pressure push the R134A into the Orifice Tube. As the pressure drops from it being released he compressor is then turned back on. The best way to tell if your system is running good is to put a set of gauges on it and check them along with the temperature in the cab. If it cycles a lot and and the temperatures are good, you could check to see if the Evaporator is clean. Here's a video on how to check that and clean it on another guys channel; ruclips.net/video/TqFf7tP7Nfw/видео.html Hope that helps. Best Wishes & Blessings. Keith Noneya
@@keithnoneya I get that it cycles on and off, but I only turns on for about 5-10 seconds then shuts off for a bit then turns back on for the same amount of time. My idle fluctuates is the main reason that it drives me crazy.
@@fixdrummerYeah I used to think that too, but after looking at some other vehicles I realized that it's supposed to do that. If it didn't do that then the High Pressure switch would constantly be turning off the compressor as well, only the lines and seals would be seeing a LOT more pressure. The higher pressures would also tend the wear the lines and seal out, not to mention the compressor rings out faster as well. I'd rather it cycle at lower pressures more often then and loose the compressor at a later date than have it chew up everything in the system at higher pressures. I hope that makes sense in the system designers reasoning for both switches. Best Wishes & Blessings. Keith Noneya
Good job. I'm wondering where the AC vacuum pump solenoid is located. Is it in the pump?
There are a couple of controls and items that effect that. Control box in the dash, the vacuum switch for the 4wd, vacuum pump, vacuum lines and tank. There are also the actuators under the dash as well. If you could be a little more specific on what your system isn't doing I may be able to help you find out what the problem is. Here's a video, not on my channel, to help:
- FWD Switch ruclips.net/video/O0131cCtXnA/видео.html
If you contact me at my YT email keith_noneya@att.net I'll send you a copy of the Vacuum Diagram of the AC system. Hope that helps point you in the right direction. Best Wishes & Blessings. Keith Noneya
Should my low pressure switch have power to one of the lead holes that you jumped? I tested low volts on my multimeter and I’m not getting any power to it and I also did the paper clip method and the clutch still won’t engage I also tried jumping the relay
Yes it should have power on one side if you are in; Max AC, AC, PAN/FLR or DEFROST. The compressor clutch gets its power from the Refrigerant (High Pressure) Switch via the Clutch Cycling Switches. The power once it makes it through those two safety switches it goes into the connector on the compressor. The top wire is the power feed (POS) from the switches and the bottom wire is the return (NEG) to ground. You can see the wiring schematic in the "Ford Super Duty F-250 & F-350 Pick-ups 1999 thru 2006" Haynes repair Manual on page 12-4. Hope that answers your question. Let me know if you need anymore help, I usually answer within 12-24 hours. Thanks for watching. Please Like and Subscribe if you want to help my channel grow. It helps even if you never come back. Best Wishes & Blessings. Keith Noneya
Refrigerant and oil leaked out of the original FS-10 compressor of my Ford Excursion which I suspect was through the shaft seal. If the clutch still engages by applying direct power and there are no noticeable noises, is it worth changing the seals or is buying a remanufactured unit a wiser choice?
Super question. If it has a ton of miles on it, I'd replace it. If it doesn't have a lot of miles and you're on a budget change the seal a dryer. Whether you replace it or not I'd pull the Orifice Tube out and clean it and put it back in. To do a reliable job you'll probably need to take the compressor off and dump all the oil out then put fresh oil in. There's a tag on the front of the truck grill that should tell you what type of oil and how much to put in. Go to an Auto Parts store and rent an AC Vacuum Pump, Pull a vacuum let it sit for 30 minutes and check the gauge to see if the pressure has dropped, if so it has a leak. Then install your refrigerant if you don't have any leaks. Thanks for watching and glad the video helped. Best Wishes & Blessings. Keith Noneya
So I’ve got low pressure . But the r134 a seems to still not take . Should I evacuate and re install . The compressor is just going on and off if I jump it it stays on
Hi X Rasta sorry for the late reply I was away from my emails for a few days. Most likely the switch is either bad or you do have Low Ac Levels. Sometimes if the system won't take anymore AC it's because it's either overcharged or the valve connector you're using is bad, I've had a good set of gauges or so I thought and it turned out to be the Low Pressure Valve was internally clogged and wouldn't allow the R134a to go into the Accumulator. If you can't figure it out take it to a professional and have them do it for you. Get an estimate and try and fix it yourself. Just tell them you'll have to save up or something. You can rent the Vacuum pump and the gauges from AtutoZone or another Automotive Parts store. Hope that gives you some ideas. Best Wishes & Blessings Keith Noneya
That truck needs a new serpentine belt quick...
Yeah it did and got one right after the video. I ran it until it broke then put the one behind the seat on it. Then purchased a new one and put it behind the seat until it's needed. I try to keep spare parts that don't take up much room or have a long lead time to get in the garage or behind the seat for quick and easy repairs. Thanks for watching hope the video was helpful, despite the belt distraction. 😂😂 Best Wishes & Blessings. Keith
I have an 09 trailblazer what could possibly my issue? My ac is cold from a cold start will cool for about 15 to 25 minutes then starts to blow hot air refrigerant is fine and worked better once I put new ac and ac/clutch relays in the fuse box stays colder longer but still shuts off after awhile? Should I replace low pressure switch or?
I had a similar issue and I believe my problem was a dirty Evaporator. When it gets full of dirt and you run the AC the water builds up on the dirt and dust on the Evaporator. When that happens the Evaporator can't cool as well and the pressures drops and the Cycle Switch kicks it out. That's my theory anyways. Try cleaning the Evaporator and then checking the pressures again. The good news is you don't have to drain the system or pull a dash to fix this. Ford did this part right and they put the Evaporator in the engine bay where it can be reached & cleaned without opening the system. Cleaning is not as easy and it looks in the video link I'm sending you, but it's doable. Try "Living Our Dream's" video here: ruclips.net/video/TqFf7tP7Nfw/видео.html Hope this helps. Best Wishes & Blessings. Keith Noneya
The switch inside should be closed?
Mines going on and off
I jumped the wires and she stayed on hooked up r134a max ac only issue is my vacuum pump is inoperable so it’s stuck on defrost is this an issue ?
Hi again X Rasta, if it's only coming out the Defrost it's the 4wd Switch on the passenger fender or you have a vacuum leak somewhere. If you don't have 4wd then it may be the Vacuum Pump on the Passenger Fender. So a search for that problem on RUclips and watch a few of those videos. If it's the vacuum pump it's an easy fix. Best Wishes & Blessings. Keith Noneya
Hi Great Video overall, it's good to have another person inside the cabin while you video the clutch engaging or not.
I have a 2003 F150, no cold air, the R134 pressure seems enough as it is in the green area. you did not cover the case where the clutch engages for 30 seconds and then dis-engages and keeps cycling like this. This cycle is also observed on the refill gauge as well the need creeps in the middle of the green the kicks the left. If the high pressure switch is only meant for safety ie. extreme pressure because of some blockage, what else is commanding the clutch to dis-engage too soon? What does the PCM figure to stop the clutch in normal operating condition or is expected to be always engaged when the knob is in A/C? I did change the battery recently could that have confused the PCM? Thank you.
Well sorry I missed seeing this question for sure. Sorry I don't remember seeing it popping up that I had a notification. However this is best set of questions yet. I'll try and answer them as best I can and give you some items to check.
From your description the system sounds normal. Vehicle AC systems normally does kick in and out about every 30 seconds. The reason the gauge drops to the left into the green when the compressor is on is because the compressor is pushing the fluid into the Orifice at the same time the compressor is pulling it from the other side of the Orifice. The compressor ends up with a tug of war over the Orifice Tube. Meaning the compressor is pushing on one side of it while on the other side of it's pulling it or sucking it through the Orifice. The gauge with the green is attached to the pulling/sucking or low side which is AFTER the Orifice. So as the compressor pumps the pressure will drop into the green to about 45-55 psi if the outside temperature is about 80 degrees. If it drops into the white area its really low on R134A or has a blockage before the orifice somewhere.
If all is operating normally in the green, at the same time this is happening the pressure on the high side is building up, you can't see that because you probably don't have a gauge hooked up to see that. That pressure is normally around 175 - 210 psi if the outside temperature is around 80 degrees.
When the compressor shuts off the pressure on the high side will start to bleed into the low side via the Orifice and the pressure on the Low side where the green gauge is will begin to rise. At the same time the High side pressure will start to drop as the pump is not running to push it up. So what's happening is when the pump is not running both sides try to balance to the same pressure through the Orifice.
So as long as the temperature in the vehicle coming out of the vents has air that is approximately 30 degrees cooler than the outside air your system is operating normally, and the compressor should cycle about every 30 seconds.
If it kicks in and out about every 5 seconds that 's to fast and is most likely a result of an improper charge. A set of gauges will definitely help tell you. If it's just a little low (Under Charged) or if it's just a little hi (Over Charged) it will kick in and out quicker. I hope my explanation was helpful, if not try and find some videos that describe how a vehicles AC system works. Then get back with me and well try a few things to narrow it down. My biggest question is, is the temperature coming out the vents about 30 degrees cooler than the outside air? If it is your system is operating normally. If you're unsure take it down to the local AC shop and have them give it a quick check up. Most of the time it's about $30.00 buck to have them take a look at it and maybe put a little R134A in it. Let me know if I need to try and help you more or answer more questions. That's what my channel is all about. Best Wishes & Blessings. Keith Noneya
@@keithnoneya Thanks for articulating great details on the push and pull function of the compressor.
My A/C was blowing hot air in hot 90F weather.
I did take it to a shop and paid $126, they said it was low after all :(, he also said he added a die in case it leaks in the future.
The single cheap gauge of the refill kit scared me and was told overfilling could blow a hose, and that's where I went wrong.
I should have used the dual gauge kit and vacuum pump I borrowed but again I had not hit on a good video about its usage (my 1st time with A/C).
To confirm, (A) When the pressure maxes out (175-210 at 80F) is it a 30 seconds timer in the PCM or the high pressure switch that shuts off the clutch or (B) ?
(B) the cycle on/off of the clutch is a direct result of the low pressure switch (via PCM), when the compressor max out the high pressure line, the low pressure must drop below the low pressure switch setting. (by design it takes 30 seconds to bleed and equalize thru the orifice).
(C) What is the typical low pressure switch trigger?, I think I heard in some video 20 PSI?
(D) At rest, everything OFF, both lines would equalize to what typical pressure? This compressor tug of war would explain the cycling :) I will verify now that I have cold air, that it is indeed cycling about every 30 seconds. Thanks again.
@@keithnoneya On the 2003 F150 I checked with a flashlight from underneath and counted over 3 minutes and the clutch did NOT stop turning at all. It runs continuously whether in normal AC or Max AC setting (both in Hi Fan speed) How do you explain that?
A temp probe in the vent reads 63F and 58F on Max AC knob. Outside temp today is 92F
However, our 2005 Honda Odyssey (never AC serviced) does cycle the clutch and the electrical fan shuts off about the same time.
At the vent it blows an incredible 39F
See my earlier questions. Thanks.
@@mumtiTV Yep sounds like it was just on the verge of being to low.
I've done a lot of vehicle AC repairs and have had great success doing it. Primarily because I do my research/homework on what i'm going to do before I do it. I am a self trained technician. I don't do this for a living and the other reason i'm successful at it, is I ask my friends who are Licensed technician and have either OWNED their own AC business or are currently working professionally in the field of AC/HVAC systems. So although I know way more than your average person on the street I'm not a professional so take what I say with a grain of salt and ALWAYS do your own research before you do something new. You'll have a lot of fun learning it and get to save a lot of money as well. So here's my opinion you your questions.
- My truck cycles about every 30 seconds and so does my 2014 Nissan Murano, I do find it irritating.
- My trucks AC today, I just checked, is putting out 44 deg at the vents and it's 81 deg's outside right now. I suppose different AC systems will act differently depending on the control systems used.
- The difference in temperature for the AC & Max AC is: Just AC uses outside air and has to cool that before it comes into the cabin area & Max AC recycles the cabin air that's already been mostly cooled.
(A), (B) & (C) - In my truck, 2001 Ford F350 and most vehicles, the Low Pressure or Compressor Cycle Switch cuts out around 24.5 psi and turns back on around 43.5 psi. The operating pressures are normally stamped on the switch itself. With that said the pressure you refer to (175-210) are not the max pressures for the switches, those are the recommend or expected pressures of a properly operating system at 80 deg's.
- The High Pressure Switch normally opens at 460-490 psi and closes again at 230-290 psi, and again the operating pressures are normally stamped on the switch. I "suppose" the 30 second cut off of the compressor can be by either switch if the pressures go outside of the operating pressures. So I can't really answer that one. But I know it's normal for my truck and my Nissan as they cool great and seem to work just fine at the approx temp of 30 deg's below the outside air temperature.
(B) The use of the PCM to control the AC System & Radiator/Condenser Fans is dependent on the vehicle year and manufacturer of the vehicle. Typically the newer the vehicle is, the more likely you are to have both the ECM/ECU and the PCM or TCM control the AC System Components. Some vehicles actually use vacuum to control the vents and at WOT (Wide Open Throttle) the ECM/TCM or low engine manifold vacuum to cut the compressor off to allow the engine to use the max available horsepower of the motor. I had a 2002 Grand Caravan and a 1991 Dodge Dynasty that this happened to all the time. This is also very common in trucks that are pulling up a hill or romp on the throttle to pass someone on the highway.
- My vehicle relies on the two Pressure Switches, the TCM (Transmission Control Module) and the WOT Throttle Position Switch. Of course there are relays and fuses in the system as well, but in my system those are the major components that turn the compressor on and off.
(D) The Equalization Pressure (my best guess) should be a little lower than 50% of the maximum recorded pressure of the system while operating. The reason for the lower than 50% is when the system operates the high will actually we a little higher because of the heat in the compressor and high pressure lines when operating. When you shut the system down that extra heat is removed.
I hope this answers most of your questions and that I got them right from what I know from either reading or my own personal experience on AC systems in vehicles.
There is a whole world full of some really cool AC systems and the different gasses they use and how they use those gasses to keep us cool. Thanks for some really good questions and watching. As always feel free to ask more questions or let me know of something I missed. Best Wishes & Blessings. Keith Noneya
Keith, do you know the location of the low pressure switch on a 2016 chevy cruze to do this test?
Well I looked around on YT and couldn't find it, so I'd ask these guys who made several videos on the Cruze AC systems. ruclips.net/video/Ld4eraN61Ck/видео.html
Here is a question... how do you know which wire engages the clutch, ie. ground or + wire? Will you see only voltage coming through the wire when then the AC turns on? So if you take a volt meter, unplug the two wires in their harness from the compressor and check which one (looks like green and red?) gives voltage when the AC is on right? Trying to install an e-fan in my 6.0 2005 F350 to replace the clutch fan...
Super good question. I'll look in the schematic in the service manual when I get home. Haynes has a copy in the back if you have one. If you don't have one and want one, I can email you a picture of it. Send an email to my channel email here: keith_noneya@att.net and I'll email you one for future reference. Don't worry I won't put you on some mailing list or send you a ton of crap or anything like that. It's just for the picture if you want a copy. Either way I'll still try and answer your question when I get home in about 3 hours. Not shown in the video it the high pressure switch. Those go bad too. Without the engine running if you pull the connector off and put a meter leads on it, it should read a short. Low pressure if you have a good charge should also read a short, on the sensor itself. Either way I'll do my best to walk through this with you and help you find your problem. Best Wishes and Blessings. Keith Noneya
Hey Alp, the 12vdc comes from the AC switch on the dash, to the Low or Compressor Cycle Switch, to the High Pressure Switch then to the Powertrain Control Module (PCM) then to the Fuse Panel Wide Open Throttle AC cutoff Relay or (WAC) then to the compressor clutch coil. The connector on the compressor has two contacts in it. The top one is the 12Vdc supplied by the switches and relays, the bottom one goes to ground. If you're going to run a fan off the AC switched low pressure or Compressor Cycle Switch I would run that to a relay and have the relay run the fans from the battery. Also don't forget to put a fuse in the line and put a parallel bypass Thermal Switch so that when the engine gets hot the fans will come on regardless if the AC is on or not. Hope that helps answer your questions. Best Wishes and Blessings. Keith Noneya
I have a few questions;
1. How long can I run the ac with the bypass?
2. How do I know if the pressure switch is N/O or N/C when buying a replacement if it doesn't have a part number, or is not in the auto system computer?
I have a semi with an APU that keeps giving me a Low pressure fualt reading.
I put ac in the system before starting to troubleshoot, so most likely it's overcharged now.
What the AC is doing:
clutch turns on for 3-5sec. before it disengages.
After 3-4min. It gives me a low pressure reading on the unit, and the clutch is disconnected for safety.
Troubleshooting:
* I found out the fan was not = working and replaced it.
Clutch still engage for only 3-4sec.
** bypass one of the pressure switch and noticed that the clutch will stay on for a longer period of time. (Seems to be the problem).
= not sure how long I can run it with the bypass, so after 15sec. I pulled it out.
Need to know if it's overcharged, if it will damage the system if left on too long with bypass?
Glad you asked that question, it's a very good and intelligent one.
1. I would not run the bypass more than 10-20 seconds at a time. The system is designed to switch on and off every few seconds as it's doing. That's why the switch is actually called the Clutch Cycle Switch, but most people still call it the Low Pressure Switch. So the clutch will cycle on and off 10-20 seconds at a time and that's normal.
2. Most Low Pressure or Clutch Cycle Switches are NO and will have the open and close pressures stamped on the side of the switch. High Pressure Switches are NC and will also have the open and close pressures stamped on the side of the switch as well.
Some systems are coupled into the computer but most are not for Light Trucks, I do not know for a Semi Trucks.
* It sounds like that the fan was definitely your initial problem, and the Cycle Switch sounds like its working to me. If you have another truck with a working AC System just like yours, open the hood, run the AC and compare them and see if there is a difference.
** If you bypass one of the Switches at a time, the system should run until the one that is not bypassed will cause the system to cut out. If in doubt on which switch is bad change them both.
= Again I wouldn't run the bypass more than a 10-20 seconds at a time.
For sure if the system has a major undetected pressure issue don't run the system in bypass mode more than a few seconds or you can blow the AC line. The only SURE way I know to tell if its overcharged is to put a set of gauges on it.
=== Another way to guess the pressure is right is to put a low pressure gauge on it and let a little of the refrigerant out until the pressure reads slightly low. Then add just enough refrigerant until the low pressure reads right for the outside temperature. If the system is charged correctly the system should cool the cab down as normal and the clutch will cycle on and off every 10-20 seconds. It's better to have the system a little low than run the system in an overcharged mode with possibly bad pressure switches.
== Here's what I would do in your situation.
1. Make sure the Condenser and Evaporator are both clean, don't forget the Cabin Filter too, if your truck has one. If they are clogged the system with cut in and out more often and won't cool properly.
2. Change both switches. NOTE when changing the High Pressure Switch the, one closest to the Compressor, the Schrader valves like to stick and let all the refrigerant out. So be ready with a new seal and some Refrigerant Cans to recharge it. You might want to wear gloves for that so you don't get frost bite.
3. Rent or buy a set of gauges to fix it.
4. If buying a set of gauges is out of your reach, take it to an AC repair shop and have them check the pressures for you. Some shops will do a quick check it for about $35.00 US.
5. If that's not possible try to do the "=== Another way", listed above.
Hope this answers your questions and helps you diagnose and fix your AC System. Let me know if I can answer any more questions. Best Wishes & Blessings. Keith Noneya PS where are you live?
Silly question: If this paperclip trick works, I need to replace my low pressure switch, right?
Switch plugged in = very high reading on the gauge of refrigerant.
Switch out w/ paperclip in = green reading, clutch spinning, air is cold.
Thank you very much for your efforts in helping people. Subbed.
If you put the paper clip in and the AC works normally with cool temperatures, approximately 30 degrees lower than the outside air, and the gauges read normal. Then yes I would suspect a bad Cycle Switch. Thanks for the sub and glad to help. Best Wishes & Blessings. Keith Noneya
@@keithnoneya Thanks for the response. I happened to test it all out again with the switch plugged in, all is well! Your paperclip trick to get the clutch moving with applying refrigerant worked wonders! Thank you so much!
mine won't cycle. Blows very cold. The clutch stays engaged unless I manually turn it off. & it's not on defrost.
That's odd! Most working systems will cycle. If it doesn't then either you have a bad Compressor Cycle (Low Pressure Switch) or an imbalance in the system. Put a set of gauges on it and check it. It sounds like it may be a little low on R134A. If it's low put a little in it from those AC recharge cans you get at the Auto Parts Store. The bad parts about the system NOT cycling is that the compressor wears out faster, as it runs even when the engine is revving higher, you'll also get reduced fuel mileage, those aren't good things. The good part is that you get to stay cool until the system dies. The AC system on my 2001 was ALL original Ford parts from 2001. - If you're not familiar with the system take it to an AC shop and let them know the system is NOT cycling. An experience technician will be able to find the issue quickly. Best Wishes and Blessings. Keith Noneya
I did the bypass on the low pressure switch clutches came on.
So hooked a can of refrigerate up and it shows in the red on the cans gauge. What should I do next?
Sorry for the late reply, my dad passed away and I've been dealing with the estate.
If it came on let it run for a minute with the engine on to let the system stabilize while watching the gauge. The gauge should start to drop to the green or lower pretty fast. If it drops and the AC works normal in the green while bypassed then change the Cycle Switch commonly called the Low Pressure Switch. If it runs but drops into the yellow or below add some R134A until it goes into the green. If it doesn't drop or run normally after that then you probably have a blockage or something else wrong in the system and you'll need to take it to a shop and have them give you an estimate to repair the system. Hope that points you in the right direction. Best Wishes & Blessings. Keith Noneya
or the low pressure switch is faulty / test continuity on the switch by using a multimeter
Yep it sure can be, a long with a dozen other items too. It could be a bad control panel, a blown fuse, a bad AC Clutch, a bad wire and the list goes on. The video was to primarily to show the easiest and quick way to check for low AC Refrigerant, not all the possible things that could cause an AC unit not to work. Thanks for the input though, I hope your comment does help someone find their problem if they do have a good R134A charge. Best Wishes & Blessings. Keith Noneya
I recharged my ac and it got cold and then a month later it wasn’t blowing as cold so I need to make to clutch come on is that like resetting it I’ve changed a lot of stuff out and don’t know what else I can change
Hi Msl, Lets see if I can help you get that cool AC back. I'm going to ask you a series of questions, so don't be offended since I wasn't there to help and i''m not sure which steps you've completed.
1. After changing all those parts did you pull a vacuum or pressurize the system to check for leaks. You can get a loaner vacuum pump at AutoZone by paying the deposit, you get it back when you bring the pump back. This is the most missed step and is the primary reason repairs fail after recharging. Most people skip this step after replacing a major part. I've skipped it on multiple occasions and have regretted it every time, so I don't skip it anymore. Pulling a vacuum removes moisture from the system, makes it more efficient and keeps the moisture from destroying your compressor.
2. Did you replace the seals on the parts you changed. Most of the time you can get away with not changing them depending on how old the system is. A seal kit is like $13.00 bucks.
2. Did you recharge the system and check the pressures with a set of gauges? You can get a loan on a set gauges at AutoZone by paying the deposit, it's full price. After you are done when you take the Loaner back they will refund the deposit, ALL of it including the tax. The deposit is to ensure you bring them back.
3. If the truck is that old, like mine, the Evaporator gets clogged after all those years. You can clean it and it will work like new again if all the other steps were done.
Please answer by the numbers and we'll get this figured out for ya bud. I don't have any videos up on the AC yet, except this one, so my reply may include a video from another channel on how to do something if you don't know how to do it. Best Wishes & Blessings. Keith Noneya
Did you know the year and model of this truck ? I ask because i got 2003 ford f250 5.4 gas 4x4 and i see the high pressure switch on this truck but do you know if mine has a high pressure switch as well as the low pressure switch ? Ive never seen it ? Also Im going to look up your video on pulling a vacuum but if you could tell me, are you saying a electric vacuum or can you use a hand pump (mityvac) vacuum pump ?
My appologies on not putting the year. My truck is a 2001 F350 7.3L. The configuration is the same for the 99-03 Superduty's. The High Pressure switch should be near the Compresor on the line. The Cycle or Low Pressure switch should be near the Evaporator housing on the passenger side. You should be able to find a video on the 5.4 AC High Pressure switch on RUclips to help you locate it. As far as the vacuum you need an AC Vacuum Pump to pull the system down to around - 30 PSI or inHg. You can rent one for free at AutoZone or most automotive stores. You put down a huge deposit on it, then when you bring it back they refund your credit card. So it's a free rent. The same for the Gauges as well. Hope that helps answer your question. Best Wishes & Blessings. Keith Noneya
@@keithnoneya Hey man thanks, guess im still basic on this, appreciate your info truly !!!!
@@brianblithe2271 Any time Brian, that's why I made the channel. Best Wishes & Blessings. Keith
My 2000 f450 compressor comes on and stays on. Its cooling but at idle feels a little warm. I was going to add a little freon but when i connected can with guage, low pressure said 70psi so i took it off. What's going on? Thanks
Hi George, sorry I took so long to get back to you. There's a few things that can cause that so lets start with the easy ones to fix to then the hard ones. 1. The Condenser behind he Grill is dirty or plugged up. Clean it real good and straighten the fins up. Unless it's visibly dirty I don't think this is your problem. 2. The Evaporator is dirty. This is probably your problem because there are no Air Filters in these early 99-06 trucks and it gets dirt on the water and cakes ups the fins. This happened to mine just like yours. Here's a video on how to clean it without breaking into the AC Lines. You do NOT have to let the R134A out to clean it, Ford did this right. ruclips.net/video/TqFf7tP7Nfw/видео.html 3. The compressor valves have gone bad. In this case you'll need to let the R134A out and change it. I'd also pull and clean the Orifice Tube, there's a video on how to do that "After" you let the R134A out on my channel. Of course you'll have to pull a vacuum and use a set of gauges to refill your AC System. Just make sure clean the Condenser behind the Grill and the Evaporator in the Clamshell next to the Passenger Engine Valve Cover in the video. Let me know if you need anything else and I'll see what I can do the help. Best Wishes & Blessings. Keith Noneya
@@keithnoneya thank you so much for your reply. I will try your recomendations!
@@George-mw7xk Anytime George! If you need anything else, just let me know. Best Wishes & Blessings. Keith
So what if it doesn’t turn on by jumping that switch but it is full ? Mine only turns clutch on when I bypass the relay but when I use another relay still won’t work and only works directly jumping it (why?)
Good question. If you jumper the cycle switch and the Compressor comes on then the pressure is low or the switch is bad. Time to put a gauge on it. What year is your truck?
So only turns on when o jump the relay not the switch and the truck is an 05 Ford f350 6.0 diesel
i HAVE A 2003 f-250 i PUT THE a/c ON WHEN I LEAVE WORK , IT IS NICE AND COLD FOR 5 TO 7 MINS THEN IT STARTS TO BLOW HOT AIR.I TURN IT OFF OPEN THE WINDOWS AND GO HOME IT SETS IN THE DRIVEWAY FOR 2 HOURS OR SO START IT UP TURN ON A/C AND IT BLOWS COLD AIR AGAIN FOR ANOTHER 5 TO 7 MINS AND HOT AIR AGAIN !! I PUT 2 CANS OF REFRIGERANT IN AND IT MADE NO DIFFERENCE COULD YOU OR ANYBODY GIVE ME A PLACE TO START AT. I AM AT A LOSS.THANKS.
Hi Robert, there are a couple of things that can cause this;
1. One of the most common on this is the Evaporator (the part that pulls the heat out of the cab) gets clogged up with dirt and dust. When the evaporator starts to produce water that water gets into the dirt in the Evaporator fins and the air can't go though it easily and pressure builds in the system and "I think" the High Pressure switch disengages the compressor and the cab gets warm. The system will act like this until the Evaporator fins dry out enough to let air go through them.
2. The Condenser (right behind the grill) gets clogged up with bugs and dirt and the same thing happens.
3. The clutch or electric fan right behind the Radiator stops spinning or spins really slow and the same thing happens.
4. The Metering Orifice over time gets clogged up and the system can't get enough R-134A to run through the system fast enough and can't keep up, Same as before the pressure builds and the system safety switches kick in to keep the system from blowing a hose.
*** Corrective Action ***:
1. Clean the Evaporator, here's a link on how to do it. ruclips.net/video/TqFf7tP7Nfw/видео.html The nice part is you don't have to vent your R-134A to do it. The bad part is it's a real pain in the butt to do, but definitely doable and worth the effort, even it that's not your problem it will only help your system to cool faster when it's fixed.
2. Pull the Grill and clean the Condenser here's a video on how to pull the Grill ruclips.net/video/gTHw6NuuMic/видео.html
3. Is a little more complicated depending on if it's electric or belt driven. sorry I don't have a link to video on those. You'll need to search around and watch some videos on how to do that.
4. Will require you to get the system drained, a set of gauges, a vacuum pump, new seals etc. etc. If you're not familiar with doing the AC either learn a lot then rent the tools or take it to professional to get that done. Hope that points you in the right direction. I'd clean the Evaporator to start with then see if that fixes it, then go from there. Best Wishes & Blessings. Keith Noneya
Thanks for posting the video. It is very informative. I have a question regarding my 2007 Ford F-350 6 litre turbo diesel A/C. This vehicle mostly sits summer and winter so I expect it to be low on A/C coolant fluid from time to time. This time when the A/C was blowing warm air I had a look at the compressor and it was cycling every 5 seconds. I put on the gauge + bottle from a recharge kit on the low side. With the engine running I saw the pressure swing back and forth from 25 to 70. I added a 6 oz bottle of fluid and saw the pressure steady to 35 = the middle of the green zone. However the compressor has quite cycling. It just runs continuously now. The A/C was providing cool air. It was not a particularly hot day, maybe mid 60’s. I have noticed in the past that if I left the A/C running continuously, it seemed to quit working, like the core iced up or something. After turning it off for a while - 20 minutes or more - it would resume working. Do you have any suggestions regarding this? Thanks for any help.
Hi J. 35 psi sounds about right for 60 deg's, I would check the cabin air filter. If they get a little clogged and get wet they will slow the air flow. Next check the Evaporator in the clam shell housing in the engine bay on the passenger side. The Low Pressure fill port on the accumulator should be hooked to the Evaporator Line. Even with cabin filters the Evaporator can get a little clogged sometime, especially if you don't drive it and mice get in there. I believe there are 11 screws that hold the clam shell closed plus the ones holding the Accumulator Dryer. You should be able to open the clam shell up and clean it, WITHOUT removing or breaking into the lines. You'll have to possibly remove the passenger Inter-cooler tube, at least I did on my 7.3L. You can try this guys video on how to open it up and clean it here: ruclips.net/video/TqFf7tP7Nfw/видео.html.
When I pulled mine open it was about 50% clogged and I had the same problem as you. I don't have that problem anymore. Don't forget to check the Condenser in the front behind the grill, make sure all the fins are clean. I hope this helps get you up and running better. Best Wishes & Blessings. Keith Noneya
PS some truck didn't come with the Cabin Filter, like my 2001 had none. I'm not sure on the 200, but I think it did. Let me know if you need anything else, glad to help. Keith Noneya
Keith, Thanks for the prompt reply. I ended up pulling back the blower fan about 8 inches, which ends up being quite easy - only 2 bolts for a vacuum device and the three for the fan. I could get a $20 USB endoscope attached to my computer in to have a look around the evaporator fins and they are clean. No sign of a cabin air filter to protect anything of course. I have decent A/C now for what remains for the summer here.
Is the low pressure port where the schrader valve is located. thanks George
No it's on top of the Accumulator Dryer under the black cap that I point to at about time index 3:35 through 3:55. Now it does have a Schrader Valve inside the port but so does the low pressure Cycle Switch, so I used the time index to make sure you get the correct Schrader valve. Hope that helps point you in the right direction. Best Wishes & Blessings. Keith Noneya
@@keithnoneya Thank you so much. i noticed there are threads up at the top of the accumulator low pressure port but I believe the valve is lower? I have been trying to find a schrader valve for the top.
@@patchreefs The threads in the top are the ones that the schrader valve screws deep inside. Notice how far I put the screw driver in the let some of the R134A out. The top port is where you check the low pressure and fill if it's low. If you don't have any R134A in the system that port is where you can pull a vacuum or pressurize it with air or Nitrogen to find the leaks with some soapy bubbles. The lower port schrader valve is for the Low Pressure or Cycle Switch, so if you change it "Theoretically" it won't lead if you pull the switch off. This isn't always the case, so if you pull it off have a new seal and pressure switch ready to go back on quickly so you'll minimize the amount of R134A leaks out if you change it.
When dealing with pressurized gasses always wear a set of safety goggles. I did a high pressure switch on the compressor up on top on the high pressure line. And sure enough as soon as I pulled the switch off it started leaking out rapidly. I had my goggles on and had a switch and new o-Ring and it was tough but I was able to get it on before I lost a lot of R134A. We added on can and it's been good since them. Best Wishes & Blessings. Keith Noneya
If the compressor doesn't kick on with the paper clip, im assuming the compressor itself is the problem?
Most likely, but not necessarily, it could be a lot of things keeping it from coming on. The clutch could be burned out (part of the compressor), the Hi Pressure Switch, Wide Open Throttle Relay or switch, the PCM there's a ton of stuff it could be. Ohm out the clutch coil at the connector on the clutch, I think it reads around 4 ohms. I put that info in one of the other comments I answered. If I wasn't in a rush to go help my sick dad I'd do a video on how to diagnose AC problems. This video was just on how to detect Low AC, provided the rest of the system was working. Read through the comments I'm sure you'll find a long post by me somewhere oh how to do some simple tests to help narrow it down. Sorry I can't be anymore help at this time, family calls. I do have the AC schematic diagrams for the AC if you want a copy send me an email keith_noneya@att.net Also the Haynes shop manual isn't to bad and they have multiple AC Diagrams in the back. Best Wishes & Blessings. Keith Noneya
Can you give me a hand here, I have the same truck. I emptied out all of the R134a, then I attempted to refill the system with R134a, but the compressor keeps kicking on and off. The only way that I can keep the compressor running a hundred percent is if I do the same paper clip trick. Should I replace the switch? Or should I remove a shim from the compressor clutch? Or am I in for a new AC compressor?
Sure, ****Sorry for the long answer I'm about to give you, but I'm not there to help you so you'll need to know a few things to find the problem yourself. So buckle up you're about to get a crash course on Automotive AC System Compressor Cycling.
*** A little added note: On hot days the compressor will cycle on and off about every 10-20 seconds. IF the vehicle cools down, and the temperature coming out of the vents, ( in air recycle mode or AC MAX), is approximately 30 degrees lower than the outside air, then the system is operating normally. Recycle mode is when you push the little sideways "U" with the arrow on it on the environmental controls, or put the system in AC MAX. This means the air going through the system comes from inside the vehicle and not from outside the vehicle. This makes it easier for the AC system to cool the vehicle down with air that's already cool, rather than bringing hot air from out side and try to cool that air. ****
Ok on to your problem. Again sorry for the long answer!
Compressors typically cycle for 1 of 3 common reasons. Here they are with some of the underlying causes for those.
* 1. Low pressure. Put a gauge on it to check it. You can rent a gauge set at most automotive stores for free. Free in that you put a deposit on them. The deposit is usually the cost of the item plus 20%. When you bring them back you get a full refund on your deposit. Watch A LOT of videos on these if you've never used them before, or you can blow up or fry your system.
a. Low on refrigerant. MOST COMMON!
b. Orifice missing. Very uncommon, some one has to open the system pull it and then forget to re-install it.
c. Compressor seals are bad and allowing to much bypass. Mine lasted 18 years then blew last summer.
** 2. Hi pressure. Put a gauge on it and check it.
a. To much refrigerant (Over charged).
b. Orifice clogged or almost clogged. This happens when a compressor blows and is changed and the orifice is not cleaned or changed. This also happens when a owner uses a lot of stop leak to solve a slow leak. This typically is fine for one use but repeated use is disastrous. Seen this first hand on a friends truck, all I can say is wow is was BAAAD!
c. Clog in the system somewhere, usually the Orifice or Condenser behind the grill. Stop leak or compressor blew up inside.
d. Air/Moisture in the system. If the system is open for a while moisture can seep in and over time start to corrode the AC system from inside. The little bits start to clog the Orifice and Condenser. Air turns into steam and causes a high pressure but is a poor refrigerant. Always pull a vacuum after opening a system that allows air in. You can rent one for free from most Automotive Parts Store, same deposit deal as the AC Gauges.
e. AC Condenser is clogged. The Condenser behind the grill turns the AC Refrigerant back into a liquid by cooling it. If the fins are bent or if it's clogged from road debris the can't work very well so the pressure goes up.
f. AC Evaporator is clogged. This is very common on these trucks, and other large Ford trucks, even other manufactures have this problem, like GMC Safari's. This is a doable fix, but is a little bit of a pain in the but. You have to open the Evaporator clam-shell and clean it with a toothbrush, vacuum it, and wash it off with some water. Low pressure hose is fine, just put a wet dry vac hose in there to catch the water or it could end up in the truck. If you send me an email at keith_noneya@att.net I'll send you a picture of what to expect it to look like.
** 3. Faulty wiring/electrical.
a. The connectors over time get a little corrosion inside, "or" due to the constant vibration the Pressure Switch connectors/wires start to break down right at the connector edge where they go in it. This is a very common problem with the High Pressure Switch on the 7.3L. To find this one, bypass each Pressure Cycle Switch one at a time with a paper clip and then wiggle the wires by the pressure Switch. If it goes on and off you most likely have found your problem. Buy the connector at the the local Automotive Part Store along with some Environmental Splices, then change it.
b. The pressure switches themselves over time do wear out, try changing them. Caution, they are supposed to have a schrader valve to prevent the refrigerant from leaking out when unscrewed. Unfortunately those valves don't always work and when the switch is pulled it sprays everywhere. The High pressure valve often sticks and if you're not quick it can empty a 12oz's (a can) out real quick. When doing the HP switch if this happens you'll have to constantly push the green AC O-Ring back up into the switch as you screw it on, not fun!
c. Compressor Clutch Coil. These over time do go intermittent then usually fry when they short internally. On modern Ford vehicles, and other makes, they can be changed without emptying out your R134A.
d. Bad ground wire on connection going to the the AC Clutch. To find this, bypass both Pressure Switches and wiggle the wires going to the AC Clutch. If it turns on and off you have a problem.
Again sorry for the long reply, I don't really know how much you know, so I though I would give you a lot and let you pick out what you needed and go with it.
Always feel free to ask questions! My channel is about education and helping those who need it.
Keep and eye on my channel. I editing a whole series on how to completely rebuild the F250/350 series AC System. Already shot the videos, but man getting the info right and editing is a "B-OTCH". I'll have a video for each item on How to replace ALL of them, pull a vacuum and recharge your system, including finding leaks, tools, chemical, etc.
Best Wishes & Blessings. Keith Noneya
@@keithnoneya the 3 reasons you gave to why a compressor keeps cycling is key here. That's the exact information I was needing, thank you!
Thanks for the information bud. You go above and beyond for your viewers. You have my sub
@@FromThe3PointLine PS how's the system running a year later? Keith Noneya
Do not rely on the can gauges. Get an ac manifold gauge set
I agree, if you're going to do repair work on the AC system you should invest the money and get one. However in this video It's just for an indication, as most people don't have a manifold gauge set. As the video title says "How to Detect", it's not repair video that would be a whole new video. So for a quick detection or a quick fill, if low, a cheap can with a gauge will most likely get the job done until you can get it to a certified AC Technician. Best Wishes & Blessings. Keith Noneya
Hey keith, im working on a/c aswell, my problem is the clutch engages on start up but cuts off after 5 secs and stays off, have replaced dryer,compressor orfice filter, condenser, high side switch and evaporatee
Hi Marcos, it sounds like your system is overcharged or you have a blockage in the system. Here's some things to check;. 1. The Cycle Switch on the Dryer Filter should have 12Vdc on both sides when the system is operating. If not check the Low Pressure port on the Dryer. The switch opens at 24.5psi to shut off the AC Clutch and Closes at 43.5psi to operate the AC Clutch, so if it's between those two pressures it should be working. If it's low, charge the system and check for leaks. 2. The High Pressure Cut Out Switch should also have 12Vdc on both pins as well when operating. If not check the High Pressure Port has between 290 to 460psi. It closes (or operates the AC Clutch) below 260-290 PSI & opens to shut off the AC Clutch above 460psi. Other things to check is the bottom pin on the AC clutch should be a direct wire to Ground/Chassis and the top should have 12vdc on top when operating. Use your multi-meter to check it connects to ground. If you don't have a meter you can use a 12V light bulb with wires on it. Connect the shell of the light bulb to the ground wire you want to check and the center or other end of the light bulb to a positive wire you want to check for power. You can also use a cheap mechanics light that you can get from the auto parts store, like this one; www.autozone.com/test-scan-and-specialty-tools/circuit-tester/p/dorman-conduct-tite-86599-circuit-tester/1080850_0_0 $7.99 One more thing to check is the method in the video. Turn the Key on but DON'T start the truck, then turn on the AC and see if the Clutch comes on and stays on. If it does you most likely have a pressure problem. Let me know if I can be of anymore help. Best Wishes & Blessings. Keith Noneya
@@keithnoneya thanks for replying keith, i have done your test in the video and the compressor clutch does not activate. on start up lower side is in psi range but high side never reaches pass 150, after 5 secs pressure settled at 100
@@keithnoneya im also wondering if flushing the system with the switches still installed could damage them or cause the build up to hide in the pressure port tubing
Have also checked fuses and relays, obd reader does not find connection aswell
@@marcoscoriano6927 Hey Marcos, did you check the voltages on the pressure switches to see if they have 12vdc when the system is turned on in the cab? 100 to150 psi should easily turn the High Pressure Cut Off Switch on. Depending on your year your WOT (Wide Open Throttle) Switch could be deactivating your AC Relay. Send me an email at keith_noneya@att.net and I'll send you some schematics diagrams to look at. You could just have a bad Clutch Solenoid, that when it turns on it gets hot and opens. To check that, turn the AC on with the truck off and probe the top wire in the Clutch connector and see if it's 12vdc. If it is and the Clutch is off you either have a bad clutch or a bad wire to ground. Ground is the bottom wire. Check those voltage with the truck off and the AC on and get back with me and we'll go from there. Best Wishes & Blessings. Keith Noneya
My problem is just the opposite. The AC system on my truck was open and not running for several years. The ac manifold was ruptured, and snow/ice got into the compressor etc. I replaced the compressor, condenser, accumulator and manifold hoses, and tested. It held vacuum, so I took it to a shop to charge. It cools fine again. The compressor clutch engages and disengages on the initial start up as the PCM runs its' tests, but then engages and never cycles. It is engaged regardless of the AC being turned on or not. Is this something I can do or is it a shop situation? It is killing my MPG, and cold weather is not that far off.
What year is your truck?
2002 F150 5.4L
@@tarlcabot5108 Are you familiar with using automotive schematics and using the shop manual?
and do you have a multi-meter for checking voltages, or a automotive test light?
@@keithnoneya I have the Haynes manual, but haven't seen it since I moved a couple years ago. I have a multi-meter and might be able to work my way through a schematic.
@@tarlcabot5108 OK, I don't have an F150 but most systems have the same components, just their locations are different places. Take a good picture or scan a picture of the diagram and email it to me; keith_noneya@att.net and we'll try and walk through it. I'm not a certified AC tech, but I've been working on vehicles for over 35 years and I'm a retired Aircraft Electronics Technician and Aircraft Test Set repair technician. I've also fixed quite a few AC units and troubleshot quit a few vehicle electrical problems. The hardest part is finding the component connectors.
We may find it in a day, or it could take awhile. Either way it depends on how fast you want it repaired. If we don't fix it for winter, but I think we will, just unplug the compressor until we can figure it out. Best Wishes & Blessings. Keith Noneya
I'm having such a hard time. I have a 2000 gas excursion, the compressor is running(It turns on and off), the system is full, but it only blows luke warm air.
You may have to put a refill bottle on it to see if it's barely low or overcharged. The other possibility is the Evaporator is clogged and needs to be cleaned. You need to put a set of gauges on it to check the pressures. Also check the Condenser to ensure it's not clogged too. Hope that points you in the right direction. Best Wishes & Blessings. Keith Noneya
@@keithnoneya Thanks for the tips, I will try that.
@@keithnoneya Thanks for the tips, I will try that.
Wheres the video for leaking? I put the cans in and within a week mine runs out. Crazy it worked great for years.
Hey DYI I haven't posted it yet, but, I use the same method as ScannerDanner, it's cheap and very reliable. Here's a link to his video, ruclips.net/video/J6DSpx1V3Ms/видео.html I'm sure it will help you find it, save you a trip to the AC guy and keep you from draining your bank account. Make sure and read the description (SHOW MORE) tab too, it has some good information in there on how to get/rent the equipment ect.
Let me know if I can help you in any other way bud. Best Wishes & Blessings. Keith Noneya.
Hey genius... if you mention a link, *make sure not to forget to post the link.*
@@gavinvalentino6002 Wile E Coyote here! "You're absolutely Correct", OOOOPS Man I can be such a ditz at times. Figured out what you were talking about. Sorry about that. Here's the link to ScannerDanners video: ruclips.net/video/J6DSpx1V3Ms/видео.html
Also, here's a link to some of those Recharge Kits if you need to get one. www.amazon.com/s?k=ac+recharge+kit+for+car&crid=1M0E6PRQW0HU7&sprefix=ac+recharge%2Caps%2C226&ref=nb_sb_ss_ts-doa-p_4_11
Hope that helps, and hope you found the rest of the video useful though. and again sorry for being a Ditz! Best Wishes & Blessings. Keith Noneya PS I
I'm having this issue tho mines it's reverse, the clutch stays engaged and there's pressure in the system, even when I take off the ac clutch relay out, it's still engaged, not sure what's the issue, any tips??
Hey Danny answer a few questions please.
1. What year is it?
2. Does the clutch ever disengage?
3. Do you have a hand held volt meter?
Let me know and we'll go from there.
@@keithnoneya it's a 2011 Toyota Corolla 1.8L, and it stop disengaging when I noticed it wasn't throwing cold air, and I'm sorry I don't have a volt meter
Meaning it never disengage, it stays cycling with or without the ac being turn on
I have to take care of something for about an hour or so, I'll help you when I done taking care of that.
@@keithnoneya ok thank you very much
What could be wrong if you jump it at the low pressure switch with a paper clip and the compressor does not click on?
Hi BC, sorry I've been out of the house all day.
If the AC Clutch is not clicking on with the AC ON and the paper clip trick then the AC Clutch Coil is not getting power, missing a ground, the AC Clutch Coil is burned up, the High Pressure Switch is bad (Open) or there is a wiring or control issue somewhere.
Here's some quick checks you should be able to do;
1. Check the fuses.
2. Test the High Pressure Switch. With the Key ON to MAX AC engine not running.
a. Using the Test Light push the tip into both wires one at a time on the connector connected to the switch, both wires should light the Test Light. I only one lights Change the Switch. If both wires light up when poked then the switch is good.Check power to AC Clutch Coil.
3. Check the Power at the AC Clutch Coil.
a, Turn the ignition key to ON with the engine NOT running.
b. Turn the AC ON to MAX AC.
c. Use a Test Light and connect the clamp to the AC Compressor metal body or the Negative Post on the Battery.
d. Poke the Test Light tip into the top wire on the AC Clutch Coil connector. It's on the AC Compressor. If the AC Clutch Coil is getting power the light should come on. If the light does not come on then you have a bad fuse, relay, control panel or a broken wire somewhere.
4. Check the Ground Return to the AC Clutch.
a. Connect the Test Light Clamp to the Positive Post on the Battery.
b. Poke the Test Light tip into the bottom wire on the AC Clutch Coil and it should light. If it lights the wire to ground is good. If it doesn't light then the wire is bad, find the break in the wire.
5. Test the coil.
a. If the Test Light Lit in both tests then the coil is bad or the connector isn't connecting to the pins on the coil.
b. Pull the connector off and check the pins in the connector, and the pins on the coil for corrosion or damage, and correct the problem.
c. If you have a meter check the pins on the coil it should be around 4 ohms, if it's not around 4 ohms or open then change the AC Clutch Coil. Look up how to change an AC Clutch Coil for your year of truck.
6. If all the test come out good take it to an AC Mechanic.
Hope that points you in the right direction. Best Wishes & Blessings. Keith Noneya
@@keithnoneya wow. Phenomenal response. And thanks for the direction!
@@bccole2343 You're welcome BC. You're also welcome to email me with pictures and questions as well. I enjoy helping people and meeting people on line too. Heck I even had a subscriber who lived in my town ask me for help, Mike Smith. We changed his front Hub Bearing Assemblies, and fixed his truck AC and some other goodies too. He's a pretty cool guy. After we got done fixing his truck him and his wife invited us over for dinner and we had a great time. So if I don't know the answer to your problem I'll help you find the answer or point you in the right direction. Best Wishes & Blessings. keith_noneya@att.net
Oh OOPS one more thing I forgot to mention, you have to jumper the Low Pressure AC Cycle Switch when you do these test. If you need a copy of the 99-03 AC wiring Diagram to help you understand what's going on, send me an email and I'll email a copy of it to you. Best Wishes & Blessings. Keith Noneya
Hey, sorry to bother.... but any ideas on ...when I put the "can gauge" on....it's reading SUPER high pressure...like 160-170....and no clutch action at all while running...Thanks Jason....!
If the clutch is not coming on and your at 160-170 psi the system is probably over pressurized or the system has balanced out since the clutch hasn't engaged the suction on the low side and the pressure on the high side. Put the gauge on it and bypass the low pressure switch with a paper clip like I showed in the video. If the compressor comes on and the pressure pressure doesn't start to immediately drop then pull the paper clip and take it to an AC shop. If the pressure drops to about normal then and starts to cool, change the Low Pressure switch. If the pressure drops below the normal pressure and the compressor is running, add some R134A until it charges to the normal pressure. Check it after a few days and see if the pressure stayed the same. If it does you should be good to go, if not and the pressure is low again you have a leak. Fix it, pull a vacuum and charge the system. Hope that helps point you in the right direction. Best Wishes & Blessings. Keith Noneya. PS you can rent a vacuum pump at your local Automotive Parts Store, Ie. AutoZone. Let me know if you need anything else.
@@keithnoneya Thanks SO much for your time on that...! I really appreciate it! I bypassed both low and high and changed out the relay with another one... clutch is free spinning....but did not come on at all.... only other thing I can think of is check for voltage at the compressor connector...( the relay under the hood is clicking though....
Sorry... and just an fyi...it was working fine a few months ago....and it's just been sitting not drivin....(I know not good ...lol...but...idk...just crazy....(like all of the sudden....) I did "bleed" the pressure on the low side and burp the high side down to like 70- 100 to see if it would help....but
@@jasonherman4833 The low and high sides when the compressor aren't running equalize. So the low & high sides will both approximately around 100psi until the compressor starts to run. Short the switches again and put the positive lead on the compressor connector and the negative on the compressor body. Turn the AC on in the truck and you should have 12vdc on the connector. If you do the coil is probably bad on the compressor. You can change it without changing the compressor. Best Wishes & Blessings. Keith Noneya
@@keithnoneya Man.....THANKS SO MUCH FOR YOUR TIME AND HELP.....! I REALLY APPRECIATE IT! I'll do it tomorrow...! Silly question.....can I do that "carefully" AT the relay terminal? Or wouldn't recommend that?
It's called refrigerant not AC
LOL I'm usually the one pointing out specifics people get wrong! Dang it! Most people don't get it so I just use what most folks would call it. Best Wishes & Blessings. Keith Noneya
Where is the switch on a jeep grand Cherokee it is not on that little can 2003 please help
You'll need to do this search: 2003 Grand Jeep Cherokee Compressor Cycle Switch and it should pop up on RUclips. If you're still not sure let me know what engine is in it, as different engines use different set ups, and I'll try and find it for you. You gotta love RUclips! There's so much good information out there and I've met some pretty cool folks from all over the world. Let me know if you need more help. Ps if you email me a picture of your engine to my RUclips email I can get a better Idea of what engine and system you have. keith_noneya@att.net Best Wishes & Blessings. Keith Noneya
I've looked everywhere for that switch Keith if I cannot find it I have the 4.0 6 cylinder the common engines in the Jeeps I cannot find the switch anyway I've looked all over it's not on the tank I followed all the lines by I can't find it if you can please help I've searched RUclips to
I'll see if I can find it for you. Of all the ones I've seen it's on top of the Accumulator, (the tank). Take a good picture of the Tank and send it to my RUclips email keith_noneya@att.net. Don't worry I'm not going to sell your email, or anything like that. LOL Keith Noneya
Oh hey Jeannie you could post a video on RUclips and all of us will get to see your system. That may be more useful for everyone to help. Best Wishes & Blessings. Keith Noneya
What if the low pressure switch it's not working
Bad High pressure switch is not working ?
Then either the pressure is low or the switch is bad so replace it.
@@wingyip6547 If the pressure is to high it will trip, if not then it should have a short through it to power the AC Compressor. If the pressures are to high on the gauge and the short is gone then this switch is most likely good. If the pressure is normal and it doesn't have a short then the switch is bad and needs to be replaced.
ummmm, hope you replaced that serpentine belt! :)
Lol, yep Sure did. Thanks for looking out for me anyways. Best Wishes & Blessings. Keith Noneya
AC pro 58 dollars now
You can still pick them up for $45.00 on eBay.
- On eBay you can pick up a hose attachment with a gauge for $12.00 from China and a12oz for $15.00ea. Hope that helps. Best Wishes & Blessings. Keith Noneya
Please don't put sealers in your system. The rest was great
Hum I guess I missed that, typically I don't like them either except for a very small leak until you can get the parts to rebuild the system. At what time index did I say to use them, It was three years ago so I don't remember. Glad you liked the rest of the video I just slapped it together on the fly for a friend. Best Wishes & Blessings. Keith Noneya
can i have your facebook?
Hi, Grafix, sorry I don't have a Facebook account. Just this and email. Keith_Noneya@att.net I check it every few days, but my YT I check several times a day. Let me know if I can do anything else for you. Best Wishes & Blessings. Keith Noneya
How about freon or refrigerant? Just makes you sound like you have no earthly idea what you're talking about or have any business making a video about it. Just FYI
Freon has been long gone and it uses R134A Refrigerant now. I could've gotten all technical, but I just chose to use terms most people would understand. I probably should have used more technical terms but I didn't. Normally I plan my videos out a little better but like I said at the beginning it was just quick video for John. It has helped a lot of people. What did you need that the video didn't explain good enough to help you. I've repaired or completely rebuilt quite a few systems, including this one. Sorry the video didn't meet your needs but if I can help I'll give it a try, and I'll use more technical terms for you if you like. Best Wishes & Blessings. Keith Noneya