Before this video I thought of fuses as just a closed switch with no (measurable) resistance so wouldn't have thought of measuring across them for a voltage drop... I guess now that I think about it it makes sense they have to have a small resistance as otherwise they wouldn't heat and melt when there is over-current. Today's random thing I learned.
Closed switches also have a measurable resistance, everything does (except for superconductors, but unless you start working on MRI machines and stuff, you'll never have to worry about that)
Every current causes a voltage drop, it’s just a consequence of the current flow to equalize charges between poles. It’s the electrical equivalent to water pressure being reduced when you open a valve.
Exactly right. The same principal is used for the precision measurement of current. A shunt with a very low but precise known resistance is installed in series with the load to be measured. The voltage across the shunt, which is directly proportionate to the current flowing through it, is measured using the appropriate voltmeter, and is converted to amperes using ohm’s law where the current to be measured is equal to the voltage across the shunt divided by the shunt resistance.
Point #1. The voltage drop across the fuse only works on a solid draw, not intermittent as you can get burned if you measure across a fuse when the draw is temporarily off. Be careful how you use this test Point #2. How come you get the fuse and relay that's visible while standing?? I"m ALWAYS upside down in a underdash block (using my extra elbow due to yoga) to pull the component. Point #3. It's always the last fuse... sure it is.. we don't find the problem fuse and then say... ok there's the problem, now let's keep looking ; )) Honestly though Eric, your bulls eye approach is a great teaching tool and I truly appreciate the time you take for these vids... awesome!
After 20 years of doing my brakes wrong, I now do them like Eric tells us, result, I never have to touch them between pad changes, before I’d always have to disassemble and re assemble (making the same mistakes) every few thousand miles. Listen to him, he knows what he’s doing.
Hey Eric, I guess this was a freebie job because the money life was not on haha great Diagnostics. Sometimes you get so wrapped up and diagnosing a problem and you don't go back to the basics
You have enough work as it is... Knowing my own limitations, similar to people everywhere, do you have a video on how to do effective You Tube/Internet searches? Like searching to find, say, those 3 SMA videos on parasitic current draws?
Eric .... YOU are the man. You said "I hope you learned something". I did which is almost always the case when watching your vids. Thanks once again. Btw, now that it's cold (even in Arizona) I stay warm by proudly wearing my South Main Auto hoodie!
Bruce 'The Boss' Springsteen did a great number about his time working at the Relay Rebuilding Factory, genuine blue collar all the way. Brings a tear to the eye.
Absolutely informational, I’m currently in my electrical class at UTI. My next class is my final so this was perfect timing and amazing to see it from you
I've always wanted to be a mechanic since I could remember, but unfortunately I procrastinated through my life. Now I'm 40 years old and I'll be attending Lincoln Tech next month. Two very talented, knowledgeable and captivating mechanics have reignited my spark to become what I always wanted to be, which is a mechanic. Those 2 mechanics are Joe from JOE'S AUTO ELECTRIC and the man himself, ERIC from SOUTH MAIN AUTO. I want to thank you so much for making me realize it's never too late. The only thing is that I know I could only learn, but so much in school and even though they have hands-on, the hands-on out in the world is more to grasp. Yes, he would be a great instructor.
Nice dianostic. However, without a fuse box wiring diagram and knowing how to read it, it would be a bit more difficult. Good tip measuring voltage drop across the fuse to determine current flow through it! I learned a new word today 'spellamagician'
The correct diagrams are usually the harder items to find in the process. Used to be a few free places but now it's a bit limited, unless you are near or have a library membership, many have access to places like Alldata, Motor or Mitchell. Or you can opt for the DIY side of those for about $30.00 bucks a year for single vehicle access.
'And just remember folks, if I can do it , you can do it' Apparently not many auto mechanics in your region can though! I don't know what they would do without you Eric 👍
Your approach to finding parasitic draw really helped me find one in my wife's 1989 Ford Probe. Took the same approach you did to finding what fuse had current flowing. That allowed me to narrow it down to the radio. Turned out that the motor for her retractable antenna was drawing current. That antenna got broken off years ago so it didn't hurt anything to just disconnect the motor and problem was fixed. As a DIYer I would not have had a clue how to figure that out without watching your video.
not necessarily over-complicate, just that people like you and me ANALYZE OBJECTIVELY these techy things....'it is what it is' not over-think the capability of a project, circuit, wireing harness, etc.
It's my car! Mines the older style. The starting in neutral is a sign that the neutral safety switch is going, then she's going to lose reverse lights when in reverse. I love this channel always a blast to see new content!
@@machintelligence yeah, they are too expensive for the age. Luckily when I swapped my jeep from 2wd to 4x4, $400 got me a transmission, axles, lift kit, extra power steering pump, extra bell housing bolts, extra torque converter... You get the idea.
@@Kiktohero4 I might guess that you did the swap after 2008. After the cash for clunkers program there were a lot of Jeeps with (deliberately) seized engines in junk yards that had good running gear. Here in Colorado you almost never see a 2wd Jeep. Also the older ones don't rust out like in the Midwest.
It's amazing that these channels have the time to make videos for one car a day in their shops how do they make a business other places have many cars they have one car a day
During your white board explanation I norticed on its right side a decal for farmboy30117s RUclips channel for farming and automotive work and I figured if YOU like him enough to have that decal there then he is good enough for me and he now has me for a subscriber. This was another excellent video showcasing diagnostic techniques thus getting right to the source. 👍
Dude Eric congratulations on having over 500k subscribers!!! That is amazing to see such a good humble guy achieve success and have the huge viewership you do entertaining, helping, and teaching the regular people, technicians, or fellow automotive enthusiast's who enjoy these videos very very much! Best wishes to you and the whole SMA family!
I'm so glad you found the problem I felt like I was there with you trying to fix the problem. in so proud of you. I feel like they should change the name from auto mechanic to auto mechanic scientist
You’re a great teacher as you have taught me to see things like you do. First thing I thought when there was the current spike was oxygen sensor heater! Thanks Professor O!
Being an EE grad, the first thing I thought of was "It's a capacitive load." I forgot that there would be no constant draw if that were true. I have much to learn Master O.! 8-))
This is exactly why I would have no problem bringing my truck to you and say "fix it". You certainly have a gift Eric. Luckily I don't live that far away from you.
Well done buddy. I thought for sure when I saw the stray wire coming off the battery and the remote start fob that it was going to be an after-market accessory that was goofing up. Nope!
As you probably already know, XJ's have a common issue with the neutral safety switches failing. I enjoyed watching the process and the white board discussion.
Yep, this is a common issue on all Jeeps with the AW4 transmission. Most of the time a good cleaning of the contacts inside will do the trick. The reverse lights are also controlled by that NSS, so if the reverse lights on an XJ or MJ don't work that's a good place to look.
Eric O. edumacating the masses. Couldn't be more better than that. Nice tutorial. Found that my factory AM/FM radio was eating my battery by the same method. It works! It's logical. Excellent.
I've been trying to show guys the voltage drop method for over two years since I joined my place now, but they look at me like I have 5 heads. Low and behold gm just put out a video for techs that their new preferred method is a sensitive amp clamp and voltage drop across fuses. Made me chuckle. Great explanation Eric
Your diagnosing technique is very scientific and well explained. You should teach because you give those young padawans (star wars lingo) an inspiration.
Thank you Mr O for the time and effort you put into videos for us, I've thoroughly enjoyed learning more about cars from you, not to mention you're incredibly entertaining!
Just bought a MK2 Supra damn thing dies every night gotta take it to a shop to get it fixed thanks for giving me some knowledge on this really needed it.
Well, to a certain degree you would have been right, since Eric verified the draw by pulling the fuse. But it saves a little time just measuring on the fuse itself to start.
Dear doctor O, I hope you read this but I would like to thank you for your time and knowledge put into these videos. I went to a tech school in Morristown TN for almost two years I studied automotive technology and I learned ALOT but I have to say I learn something new every time I watch your videos especially dealing with electronics and diagnostics. Anybody can be a mechanic but it takes someone with skill and some “tricks from Mee-Maw” to be a true automotive technician. Thank you sir and Merry Christmas to you and your family!
I love my Ut210e clamp meter for parasitic draws, no battery disconnect necessary (and I know you can sneak the probes in under the terminal, but sometimes even the best intentions fail due to unforeseen circumstances!) and also - NO FUSES :)
It’s $200-$225 Canadian an hour for dealership rates where I live. I really enjoy your channel. I am not a mechanic . I have learnt many things on your channel that has and can save me $$$. I know when I am in over my head with a repair and go to shops . But some things are really easy to repair. Thank you .
You sir are an excellent technician. I would pay double prices to have you available in my area. I was unaware of the voltage across the fuse tip. Thats a good one to know for parasitic loss. Thanks
Who doesn't like Mary Ann more? That actress had more sex appeal in her little finger than "Ginger" had in her whole body! Playing against her nature just enhanced it.
My 2012 Chevy Colorado has a similar problem since new, battery dies in a couple of days. When it was still under warranty I had GM tow it to the dealer for repairs. The dealer then tells me the battery was bad. The next weekend the same problem. Took it back to the dealer, they then told me I don’t drive the vehicle enough.😂🤪🤪. So that was a dead end. It ended up that it was the BCM. I installed a 70 amp battery disconnect relay, works great!😁
My first car was a 51 Studebaker and that is what we had to do every night-----unhook the battery. There was a dead short somewhere. My dad took it to three different mechanics, one that specialized in electrical repair, and they all said it was the voltage regulator (6v generator system) and so this car got three different voltage regulators inside of 4 months. The amp meter still pegged full discharge 50% of the time at engine shut down. We finally gave up and sold it to another teenager for $60. He inadvertently found the problem. Any guesses?? Intermittent short in the 6v battery!! He put a different battery in it and he said it never had the problem again. 9 months later he totaled the car. A fitting end to miserable automobile. I hated that car. Now, how did the battery develop a short? Well, not all teenagers knew that at the time not all cars had the same voltage electrical systems. In the mid 60's there were still plenty of 6v cars on the road. I guess when you own a 6v car and try to jump start a 12v car it isn't so good on the electrical system of either car or, in this case, the 6v battery! Who would have thought! The interesting thing to me is that none of the mechanics tested or suspected the battery. Every single one diagnosed it as a faulty voltage regulator. Actually, I am thankful for that because that meant I didn't need to drive that hog ever again.
@@jws3925 Not possible the cause of high-current meter reading was the battery. If the battery had a short, the high current wouldn't leave the battery (that's the *meaning* of "short"), therefore it wouldn't display on the meter. That short certainly would kill the battery quickly, but if you saw a pegged ammeter, it wasn't caused by a defective battery. Possible the new owner inadvertently fixed the cause when removing the old battery and installing a new one.
Had a similar problem last month. My nephew had his truck towed over for a no start. I figured out the starter was bad, but after checking powers and ground at the starter found the power on at all times. Finally figured out he had installed different incorrect starter relay that allowed constant power. As a diy guy it took me a bit but I figured it out. I’m sure the knowledge I’ve gained from you and others helped.
It is amazing the amount of knowledge in different fields of knowledge Eric has. In order to be such a great mechanic he has to also be a master electrician. Jeeze louise, he knows a lot.
Strange as it is I have had a fuse causing a draw, cheap fuse had corroded and the goo caused enough of a current path to another point in the box it created a drain. Was a pain to find because the drain didn't stop with the fuse out. Wasn't until I used a thermal camera and saw the heat under the fuse that it showed up.
Cool. Just replaced a Bank 1 Sensor 2 O2 outside in the beautiful Canadian winter on the snow ramps. Really enjoy the fresh air, blowing snow, freezing fingers and snow up your back.😜. Heat from the torch was nice though.🤣☃️🎄
Your diagnosis is impressive! The episode gets "boring" for a KO in few seconds -- I was expecting cursing, hair pulling and tons of frustration. Seriously you were spot on from the start and I learned a lot.
one of my greatgrandkids was looking over my shoulder when i had your video on. he fixed aunts car used a test light and a dvom smart kid (he is 5 years old )just to let you know how well you explain every thing
“Gimme a match book and a nail file”...brings back memories, but I never had a nail file. If they needed to be cleaned up, just use the striker on the match book!
I've been an EE for over forty years and I just learned today that PowerPro made a chart of fuse size vs voltage drop to determine current draw.... thanks! Printed out & placed in tool box!!
@@SouthMainAuto Erik! We was having a lean supply in former USSR - no access to NAPA or Autozone, Rockauto etc. As my grandma told: Time what You have equal money what You don`t! - Do not pay to Dorman - keep in Your pocket!
This would make a great test for prospective employees to check their logical deduction skills, understanding of electrical circuits, and schematic reading ability. Might weed out the weak ones. One thing is certain, you have a real gift for teaching.
Enjoy watching you breathing life into vehicles with mileage/age that would cause many of them to be sold to an auto recycling yard. You are preventing unnecessary waste.
When I bought my used 2002 Saturn, the dealer told me something his mechanic told him, that Saturns that won't shift may have a defective $25 relay that's hidden under the batter tray on cars like mine. Change the relay, fix the car!
Tools ! Having the right tools and knowing how to use them! Your Technique and process is spot on. Great Job and very entertaining. PS My porch Ferns are still alive. High tomorrow 65 Don't miss the snow. Franklin,TN
@@BobPegram Fortunately there is no conservation law for knowledge unlike for example energy, momentum or even dirt! Someone can get loads smarter without diminishing anyone else's capacity.
Learned to drive on a 2000 Cherokee it only had oil changes and a water pump with 200k + miles that was bought new. Would still probably have it if my sister didn't wreck it a couple years ago sliding out on wet deicer. Probably one of the best vehicles ever built.
Nice concise process, and well explained. I did one that had no amp draw on any of the fused circuits, but was drawing a full amp from the battery. Eventually, I relized that it had to be somewhere unfused, and discovered (by dumb luck) that the output wire from the alternator was touching a hose clamp, and apparently managing to short a full amp through the hose, as the clamp wasn't touching any metal. Of course, I found that by burning my finger on the steamin' hot hose clamp lol. Lesson here is . . if none of the fuses have the draw, look at the unfused stuff which will be the power side of the starter circuit, and the charging circuit.
Great diagnosis as always!! On a side note: How thoughtful of the guys at FCA to place the reservoir for the windshield washer LITERALLY NEXT TO THE FUSEBOX, another quality product FCA.
Thanks man Went through a similar process on a 05 Odyssey, .6mA draw Main fuse in EC fed to PC box Verified the issue by pulling the fuse that was the suspected circuit, left the car overnight, maintained battery at 12.9v Ensured all system went to sleep, and no other possible parasitic draws. Next step is to give the customer decision to chase the problem in the circuit. Or just leave the fuse disconnected. Circuit was interior lighting, less of an issue of giving an estimate to go further. Electrical is difficult to estimate labor time even by giving a minimum charge, can get burned if the diag time is used up and try to explain to the customer. Better for baby steps with the customer so they can give an okay for further investigation Thanks Eric Always a pleasure to watch your procedures
@@Joseph1NJ And mechanics! On a Chrysler product it is likely EGR. We just check once a year to be sure that is the only code, give it an oil change and general checkover, then give it back to the wife and daughter to drive for another year!
"I'm not a spellamagician". Love it. Neither am I. I was trying to hear if the relay clicked when you were trying it in and out of the circuit. Glad you mention it in your white board wrap up. Stay safe.
I had known about the voltage drop across a fuse for quite a few years. However, I never thought to use it for an unwanted current draw. I put a clutch in a friend's Ranger pickup and I knew it had a draw that was killing the battery. Used my ammeter and found a 1 amp draw. Voltage dropped the fuses and found the problem very quickly. Thanks for the tip!
Eric have you ever thought to make little SMA stickers to go over the check engine light for customers that don’t want to fix the problem?
For the first time in my life somebody was speaking electricity to me and I actually understand!
Before this video I thought of fuses as just a closed switch with no (measurable) resistance so wouldn't have thought of measuring across them for a voltage drop... I guess now that I think about it it makes sense they have to have a small resistance as otherwise they wouldn't heat and melt when there is over-current. Today's random thing I learned.
Closed switches also have a measurable resistance, everything does (except for superconductors, but unless you start working on MRI machines and stuff, you'll never have to worry about that)
Every current causes a voltage drop, it’s just a consequence of the current flow to equalize charges between poles. It’s the electrical equivalent to water pressure being reduced when you open a valve.
Even the wires of the circuit have some resistance and cause a voltage drop. It's not big, but it exists. More current=more voltage drop.
Exactly right. The same principal is used for the precision measurement of current. A shunt with a very low but precise known resistance is installed in series with the load to be measured. The voltage across the shunt, which is directly proportionate to the current flowing through it, is measured using the appropriate voltmeter, and is converted to amperes using ohm’s law where the current to be measured is equal to the voltage across the shunt divided by the shunt resistance.
That was your classic parasitic draw. Great Job. You are absolutely right in your approach to solving this.
"Ivan would be proud." Love it!
Point #1. The voltage drop across the fuse only works on a solid draw, not intermittent as you can get burned if you measure across a fuse when the draw is temporarily off. Be careful how you use this test
Point #2. How come you get the fuse and relay that's visible while standing?? I"m ALWAYS upside down in a underdash block (using my extra elbow due to yoga) to pull the component.
Point #3. It's always the last fuse... sure it is.. we don't find the problem fuse and then say... ok there's the problem, now let's keep looking ; ))
Honestly though Eric, your bulls eye approach is a great teaching tool and I truly appreciate the time you take for these vids... awesome!
If Eric ever gets tired of turning wrenches, he'd make a hell of an instructor.
Yeah but I’m sure it doesn’t pay as well. Nothing against my vocational instructor he was great. Most of them were service technicians at one point
@@brianbrundage1598 my instructors make about 150k a year, and that’s at a community college
...or English teacher
Yes true.. other shops put me to sleep. And no hands on...
@@brianbrundage1598 .
Trouble shooting is key to any diagnostic approach. This channel has made me a better tech in my field just by watching the approach to a problem.
Best Channel Ever!!
One of my top 5 anyway. (In the auto category he has to live beside ChrisFix.)
Damn. You must be one of the best mechanics in the entire country. The speed, accuracy, and validation of your repairs are insane!
After 20 years of doing my brakes wrong, I now do them like Eric tells us, result, I never have to touch them between pad changes, before I’d always have to disassemble and re assemble (making the same mistakes) every few thousand miles. Listen to him, he knows what he’s doing.
"Classic tape over the engine light"...... 🤣😂🤣👍
SMA rocks!!!
Hey Eric, I guess this was a freebie job because the money life was not on haha great Diagnostics. Sometimes you get so wrapped up and diagnosing a problem and you don't go back to the basics
Maybe you can find time to start a side hustle teaching the “other shops” mechanics basic troubleshooting techniques.
I do... and your watching it just like they can ;)
@@SouthMainAuto I thought it was a bite but he may be being genuine. WOW
@@SouthMainAuto So, at local garage owners meetings are you the guy who says: "Yup, I've got 3 You Tube videos on that, have your guys watch 'em."?
You have enough work as it is... Knowing my own limitations, similar to people everywhere, do you have a video on how to do effective You Tube/Internet searches? Like searching to find, say, those 3 SMA videos on parasitic current draws?
@@SouthMainAuto wooozzzeerrzz that's gotta burn
Eric .... YOU are the man. You said "I hope you learned something". I did which is almost always the case when watching your vids. Thanks once again. Btw, now that it's cold (even in Arizona) I stay warm by proudly wearing my South Main Auto hoodie!
Bruce 'The Boss' Springsteen did a great number about his time working at the Relay Rebuilding Factory, genuine blue collar all the way. Brings a tear to the eye.
The classic “there’s your problem lady!”
Absolutely informational, I’m currently in my electrical class at UTI. My next class is my final so this was perfect timing and amazing to see it from you
Good luck brotha!
Good luck bro from a fellow alumni Avondale AZ campus
Good luck from a former Electrical Instructor from UTI Avondale!!
Good Luck; we're all counting on you. (Dr. Rumack, Airplane!)
I've always wanted to be a mechanic since I could remember, but unfortunately I procrastinated through my life. Now I'm 40 years old and I'll be attending Lincoln Tech next month. Two very talented, knowledgeable and captivating mechanics have reignited my spark to become what I always wanted to be, which is a mechanic. Those 2 mechanics are Joe from JOE'S AUTO ELECTRIC and the man himself, ERIC from SOUTH MAIN AUTO. I want to thank you so much for making me realize it's never too late. The only thing is that I know I could only learn, but so much in school and even though they have hands-on, the hands-on out in the world is more to grasp. Yes, he would be a great instructor.
Nice dianostic. However, without a fuse box wiring diagram and knowing how to read it, it would be a bit more difficult. Good tip measuring voltage drop across the fuse to determine current flow through it! I learned a new word today 'spellamagician'
The correct diagrams are usually the harder items to find in the process. Used to be a few free places but now it's a bit limited, unless you are near or have a library membership, many have access to places like Alldata, Motor or Mitchell. Or you can opt for the DIY side of those for about $30.00 bucks a year for single vehicle access.
'And just remember folks, if I can do it , you can do it' Apparently not many auto mechanics in your region can though! I don't know what they would do without you Eric 👍
Please never stop making content Eric. You rule.
Your approach to finding parasitic draw really helped me find one in my wife's 1989 Ford Probe. Took the same approach you did to finding what fuse had current flowing. That allowed me to narrow it down to the radio. Turned out that the motor for her retractable antenna was drawing current. That antenna got broken off years ago so it didn't hurt anything to just disconnect the motor and problem was fixed. As a DIYer I would not have had a clue how to figure that out without watching your video.
Things like this keep me coming back. I try to use the same thought process you do, but I always over-complicate everything.
not necessarily over-complicate, just that people like you and me ANALYZE OBJECTIVELY these techy things....'it is what it is' not over-think the capability of a project, circuit, wireing harness, etc.
My favorite kind of videos troubleshooting electrical current draws.
It's my car! Mines the older style. The starting in neutral is a sign that the neutral safety switch is going, then she's going to lose reverse lights when in reverse. I love this channel always a blast to see new content!
Thank goodness there are after market neutral safety switches out there. They cost North of $ 220.00 from a dealer.
@@machintelligence yeah, they are too expensive for the age. Luckily when I swapped my jeep from 2wd to 4x4, $400 got me a transmission, axles, lift kit, extra power steering pump, extra bell housing bolts, extra torque converter... You get the idea.
@@Kiktohero4 I might guess that you did the swap after 2008. After the cash for clunkers program there were a lot of Jeeps with (deliberately) seized engines in junk yards that had good running gear. Here in Colorado you almost never see a 2wd Jeep. Also the older ones don't rust out like in the Midwest.
@@machintelligence This year, actually. I've done a ton of work to it, I have done the rear disk conversion and the Big 7.
It's amazing that these channels have the time to make videos for one car a day in their shops how do they make a business other places have many cars they have one car a day
During your white board explanation I norticed on its right side a decal for farmboy30117s RUclips channel for farming and automotive work and I figured if YOU like him enough to have that decal there then he is good enough for me and he now has me for a subscriber. This was another excellent video showcasing diagnostic techniques thus getting right to the source. 👍
Your knowledge of electrical systems is downright scary smart .
I really like this kind of video.
Mostly brain work and then testing to verify the thinking.
Bravo.
There's your problem lady! There is something strangely satisfying about blurting that out once victory is achieved.
Excellent diagnostic work, Eric! The customer is lucky to have brought the car into your shop.
SMA is my favorite RUclips channel hands down
Dude Eric congratulations on having over 500k subscribers!!! That is amazing to see such a good humble guy achieve success and have the huge viewership you do entertaining, helping, and teaching the regular people, technicians, or fellow automotive enthusiast's who enjoy these videos very very much! Best wishes to you and the whole SMA family!
I'm so glad you found the problem I felt like I was there with you trying to fix the problem. in so proud of you. I feel like they should change the name from auto mechanic to auto mechanic scientist
You’re a great teacher as you have taught me to see things like you do. First thing I thought when there was the current spike was oxygen sensor heater! Thanks Professor O!
Being an EE grad, the first thing I thought of was "It's a capacitive load." I forgot that there would be no constant draw if that were true. I have much to learn Master O.! 8-))
This is exactly why I would have no problem bringing my truck to you and say "fix it". You certainly have a gift Eric. Luckily I don't live that far away from you.
Well done buddy. I thought for sure when I saw the stray wire coming off the battery
and the remote start fob that it was going to be an after-market accessory that was goofing up. Nope!
I’ve learned many things from you about modern mechanic procedures. I now don’t complain about the hourly rate my mechanic charges. Thanks Eric.
As you probably already know, XJ's have a common issue with the neutral safety switches failing. I enjoyed watching the process and the white board discussion.
That switch failed on my 92 xj.
Two of the three I had ended up with an "emergency bypass" on them because of the switch.
Changed one out already on mine.
Yep, this is a common issue on all Jeeps with the AW4 transmission. Most of the time a good cleaning of the contacts inside will do the trick. The reverse lights are also controlled by that NSS, so if the reverse lights on an XJ or MJ don't work that's a good place to look.
A logical approach to a problem is always the best way.
I do believe that you just helped me fix my old Chevy plow truck. Thanks a ton!
Eric O. edumacating the masses. Couldn't be more better than that. Nice tutorial. Found that my factory AM/FM radio was eating my battery by the same method. It works! It's logical. Excellent.
You are an excellent troubleshooter! Thanks for sharing!
I've been trying to show guys the voltage drop method for over two years since I joined my place now, but they look at me like I have 5 heads. Low and behold gm just put out a video for techs that their new preferred method is a sensitive amp clamp and voltage drop across fuses. Made me chuckle. Great explanation Eric
Thanks for "relaying" this repair experience.
In 40 years wrenching I never thought of measuring voltage drop across a fuse. Thanks for the good tip!
You are a great teacher AND diagnostician!
Your diagnosing technique is very scientific and well explained. You should teach because you give those young padawans (star wars lingo) an inspiration.
Good diagnosis! I was betting on a stuck on brake light or tail gate switch...Soooo many possibilities that can cause that same battery drain.
I can use this method to make my life easier, got a truck that kills 3 huge batteries in a few days where I work, going to figure it out soon.
Thank you Mr O for the time and effort you put into videos for us, I've thoroughly enjoyed learning more about cars from you, not to mention you're incredibly entertaining!
Just bought a MK2 Supra damn thing dies every night gotta take it to a shop to get it fixed thanks for giving me some knowledge on this really needed it.
I like your trick to measure fuse voltage. I would have started pulling fuses.
Well, to a certain degree you would have been right, since Eric verified the draw by pulling the fuse. But it saves a little time just measuring on the fuse itself to start.
Dear doctor O, I hope you read this but I would like to thank you for your time and knowledge put into these videos. I went to a tech school in Morristown TN for almost two years I studied automotive technology and I learned ALOT but I have to say I learn something new every time I watch your videos especially dealing with electronics and diagnostics. Anybody can be a mechanic but it takes someone with skill and some “tricks from Mee-Maw” to be a true automotive technician. Thank you sir and Merry Christmas to you and your family!
I love my Ut210e clamp meter for parasitic draws, no battery disconnect necessary (and I know you can sneak the probes in under the terminal, but sometimes even the best intentions fail due to unforeseen circumstances!) and also - NO FUSES :)
Yeah I have several inductive clamps but I prefer the precision of the meter myself. Especially when dealing with less that 1 amp
@@SouthMainAuto totally agreed on the precision thing! I usually deal with draws that are either around 800mA or 20mA (aka, either normal or not haha)
It’s $200-$225 Canadian an hour for dealership rates where I live. I really enjoy your channel. I am not a mechanic . I have learnt many things on your channel that has and can save me $$$. I know when I am in over my head with a repair and go to shops . But some things are really easy to repair. Thank you .
I admit I can’t always follow your reasoning when it comes to electronics. Thank you for explaining this in excruciating detail for my benefit
You sir are an excellent technician. I would pay double prices to have you available in my area. I was unaware of the voltage across the fuse tip. Thats a good one to know for parasitic loss. Thanks
Not Ginger with relays. I'm a Mary Ann guy myself.
@mchlross3 noice!
Who doesn't like Mary Ann more? That actress had more sex appeal in her little finger than "Ginger" had in her whole body! Playing against her nature just enhanced it.
Mary Ann?
Dawn Wells!
@@BobPegram Gingerrrrrrrrrr! But I'd never kick Mary Ann out of bed for eating crackers.
By a sad coincidence, the actress who played Mary Ann passed away today. Covid19. RIP Dawn Wells, 1938-2020.
My 2012 Chevy Colorado has a similar problem since new, battery dies in a couple of days. When it was still under warranty I had GM tow it to the dealer for repairs. The dealer then tells me the battery was bad. The next weekend the same problem. Took it back to the dealer, they then told me I don’t drive the vehicle enough.😂🤪🤪. So that was a dead end. It ended up that it was the BCM. I installed a 70 amp battery disconnect relay, works great!😁
How to fix battery that dies over night. Disconnect battery before night :-)
A 100% effective fix for sure haha
My first car was a 51 Studebaker and that is what we had to do every night-----unhook the battery. There was a dead short somewhere. My dad took it to three different mechanics, one that specialized in electrical repair, and they all said it was the voltage regulator (6v generator system) and so this car got three different voltage regulators inside of 4 months. The amp meter still pegged full discharge 50% of the time at engine shut down. We finally gave up and sold it to another teenager for $60. He inadvertently found the problem. Any guesses??
Intermittent short in the 6v battery!! He put a different battery in it and he said it never had the problem again. 9 months later he totaled the car. A fitting end to miserable automobile. I hated that car. Now, how did the battery develop a short?
Well, not all teenagers knew that at the time not all cars had the same voltage electrical systems. In the mid 60's there were still plenty of 6v cars on the road. I guess when you own a 6v car and try to jump start a 12v car it isn't so good on the electrical system of either car or, in this case, the 6v battery! Who would have thought!
The interesting thing to me is that none of the mechanics tested or suspected the battery. Every single one diagnosed it as a faulty voltage regulator. Actually, I am thankful for that because that meant I didn't need to drive that hog ever again.
@@jws3925 Not possible the cause of high-current meter reading was the battery. If the battery had a short, the high current wouldn't leave the battery (that's the *meaning* of "short"), therefore it wouldn't display on the meter. That short certainly would kill the battery quickly, but if you saw a pegged ammeter, it wasn't caused by a defective battery.
Possible the new owner inadvertently fixed the cause when removing the old battery and installing a new one.
@@davecc0000 Wiggle the right wire and anything is possible, good/bad, OMG its on fire lol
How to fix battery that dies over night. Conduct funeral in the morning.
Had a similar problem last month. My nephew had his truck towed over for a no start. I figured out the starter was bad, but after checking powers and ground at the starter found the power on at all times. Finally figured out he had installed different incorrect starter relay that allowed constant power. As a diy guy it took me a bit but I figured it out. I’m sure the knowledge I’ve gained from you and others helped.
Greetings and Happy Holidays from Miami Florida!!!
Christmas
It is amazing the amount of knowledge in different fields of knowledge Eric has. In order to be such a great mechanic he has to also be a master electrician. Jeeze louise, he knows a lot.
With 50+ years as a mechanic I can say I have never run into a defective fuse like that, good catch. 😂
Sherlock ( Mechanic of Auto) show his diagnosis can be understood by the common person. LOVE this channel.
Strange as it is I have had a fuse causing a draw, cheap fuse had corroded and the goo caused enough of a current path to another point in the box it created a drain. Was a pain to find because the drain didn't stop with the fuse out. Wasn't until I used a thermal camera and saw the heat under the fuse that it showed up.
Cool. Just replaced a Bank 1 Sensor 2 O2 outside in the beautiful Canadian winter on the snow ramps. Really enjoy the fresh air, blowing snow, freezing fingers and snow up your back.😜. Heat from the torch was nice though.🤣☃️🎄
"I'm not a spellimatician." I laughed out loud.
Your diagnosis is impressive!
The episode gets "boring" for a KO in few seconds -- I was expecting cursing, hair pulling and tons of frustration.
Seriously you were spot on from the start and I learned a lot.
Awesome channel ! One of the first you tuber channels I cut my teeth on, still the best .
You have a way of making most problems look easy.
How is Your dodge ?
@@maciejolejniczak151 Doing great! Just finished a video set on how to swap out the clutch packs on the rear LSD.
I would love to see same problem on Honda that’s coming.
It will probably be something different.
Thanks for pausing and letting your viewers think when you showed the increase jump when you reapplied the fuse in the circuit. That really helps.
tape over the check engine light killed me xD
one of my greatgrandkids was looking over my shoulder when i had your video on. he fixed aunts car used a test light and a dvom smart kid (he is 5 years old )just to let you know how well you explain every thing
“Gimme a match book and a nail file”...brings back memories, but I never had a nail file. If they needed to be cleaned up, just use the striker on the match book!
I've been an EE for over forty years and I just learned today that PowerPro made a chart of fuse size vs voltage drop to determine current draw.... thanks! Printed out & placed in tool box!!
Once again, I have learned. Thanks for sharing!
these are the kinds of things around here a mechanic can never fix , but they sure charge you for it , great job and great class .
"relay rebuilding factory" Otherwise known as Pine Hollow Diagnostics!!
Full Russian style!
yes comrade
@mchlross3 Yep. Ivan could repurpose that relay.
Ivan would have test drove the relay with the scope hanging out the window!
@@SouthMainAuto Erik! We was having a lean supply in former USSR - no access to NAPA or Autozone, Rockauto etc. As my grandma told: Time what You have equal money what You don`t! - Do not pay to Dorman - keep in Your pocket!
Dude you got it together. So pleasurable following your intelligent sleuthing.
Thanks as always, Eric. Merry Christmas!
This would make a great test for prospective employees to check their logical deduction skills, understanding of electrical circuits, and schematic reading ability. Might weed out the weak ones. One thing is certain, you have a real gift for teaching.
So, ya' do some pullin, ya' do some pokin, and ya' do some deducktin, and that's how you fix a car? Bullseye. Thanks Dr. O!
Enjoy watching you breathing life into vehicles with mileage/age that would cause many of them to be sold to an auto recycling yard. You are preventing unnecessary waste.
When I bought my used 2002 Saturn, the dealer told me something his mechanic told him, that Saturns that won't shift may have a defective $25 relay that's hidden under the batter tray on cars like mine. Change the relay, fix the car!
"Spella-magician" lol, able to make spelling errors disappear at the wave of a wand! 🧙♂️
Tools ! Having the right tools and knowing how to use them! Your Technique and process is spot on. Great Job and very entertaining. PS My porch Ferns are still alive. High tomorrow 65 Don't miss the snow. Franklin,TN
I am now smarter than when I woke up this morning.
And it didn’t make me mad or madder 👍
So, does that make Eric O. dumber now?
@@BobPegram Fortunately there is no conservation law for knowledge unlike for example energy, momentum or even dirt! Someone can get loads smarter without diminishing anyone else's capacity.
Squirrel!
@@peterkim5394 I was just kidding.8-))
I like the thermal camera idea.
Could that also have been why the "money light" was on because of the o2 sensors
Learned to drive on a 2000 Cherokee it only had oil changes and a water pump with 200k + miles that was bought new. Would still probably have it if my sister didn't wreck it a couple years ago sliding out on wet deicer. Probably one of the best vehicles ever built.
Scotty better watch his back and I’m not talking Kilmer, Jim Kirk would hire Eric in a heartbeat. There’s your problem lady.
Nice concise process, and well explained. I did one that had no amp draw on any of the fused circuits, but was drawing a full amp from the battery. Eventually, I relized that it had to be somewhere unfused, and discovered (by dumb luck) that the output wire from the alternator was touching a hose clamp, and apparently managing to short a full amp through the hose, as the clamp wasn't touching any metal. Of course, I found that by burning my finger on the steamin' hot hose clamp lol.
Lesson here is . . if none of the fuses have the draw, look at the unfused stuff which will be the power side of the starter circuit, and the charging circuit.
“Classic tape over the engine light.” Why fix it when you can just cover it up🤣
Now I will lay awake nights wondering what the code(s) might have been on that.
Why not leave it on? The bulb will eventually burn itself out. Just curious Eric. Did you check the code to see if the relay tripped the mil?
Who wants to take bets that the code was set due to the faulty relay in the first place
And if you turn up the stereo all of the noises go away
I use it on my Subaru, I do not need to know if the seat switch is on or off all the time. A yellow light just gets irritating after a time.
Great diagnosis as always!! On a side note: How thoughtful of the guys at FCA to place the reservoir for the windshield washer LITERALLY NEXT TO THE FUSEBOX, another quality product FCA.
Awesome sauce! Love it when you use the white board! Even a dummy like me can understand things! 😂
Thanks man
Went through a similar process on a 05 Odyssey,
.6mA draw
Main fuse in EC fed to PC box
Verified the issue by pulling the fuse that was the suspected circuit, left the car overnight, maintained battery at 12.9v
Ensured all system went to sleep, and no other possible parasitic draws.
Next step is to give the customer decision to chase the problem in the circuit. Or just leave the fuse disconnected.
Circuit was interior lighting, less of an issue of giving an estimate to go further.
Electrical is difficult to estimate labor time even by giving a minimum charge, can get burned if the diag time is used up and try to explain to the customer.
Better for baby steps with the customer so they can give an okay for further investigation
Thanks Eric
Always a pleasure to watch your procedures
Ya know, I've heard of the 'tape over the check engine light,' but have never actually seen it before.
Haha! I once brought a van with tape over the brake light, turned out to be the fluid was low. I tell you, some people aren't meant to own vehicles.
@@tinytim9453 A friend mechanic told me of it, but I had never seen it. He said it was mostly women. I'm just saying what he said is all.
@@Joseph1NJ And mechanics! On a Chrysler product it is likely EGR. We just check once a year to be sure that is the only code, give it an oil change and general checkover, then give it back to the wife and daughter to drive for another year!
"I'm not a spellamagician". Love it. Neither am I. I was trying to hear if the relay clicked when you were trying it in and out of the circuit. Glad you mention it in your white board wrap up. Stay safe.
Congrats on a well deserved over 500,000 subs 👍🏽
I had known about the voltage drop across a fuse for quite a few years. However, I never thought to use it for an unwanted current draw. I put a clutch in a friend's Ranger pickup and I knew it had a draw that was killing the battery. Used my ammeter and found a 1 amp draw. Voltage dropped the fuses and found the problem very quickly. Thanks for the tip!