Mate thank you, you are a legend. I have always get confused with relays but the way you explained it has now been implanted into my head and no longer have an issue. Champion! thanks again
Thank you for clearing up this issue for me Doug. I’ve been dreading a wiring problem for a little too long because the relays and wiring were pretty intimidating. But this clears up a lot of things for me.
The wire gauge vs. length is key. Previouslyr I didn't know that you can get away with a smaller gauge wire over a short distance. Those Derale fans come with small short wires - and people would think, 'I just match that gauge' to run the wire to where you need to go, but in my measuring I needed a larger gauge. Maybe why a lot of people complain of their electric fans not flowing enough or prematurely failing. Your built in light location is awesome!
@@BALLERXD24 8 gauge copper stranded wire. If you search the web for 12v wire gauge distance voltage drop - you can calculate the specs needed for your application.
@@MichiganRay Sorry about that. Not sure why I typed 8. I ran 10 awg from the fans to the fan controller and battery junction. I like run 4 awg to my starter which I'm sure is overkill but I assume 200amps. But yes, you can't trust anything on the internet these days. 😅
Just to clarify what you said about PWM, it doesn't exactly give you different voltages but instead gives you different duties. So for instance it will continually cycle from +12V to 0V hundreds or thousands of times per second and based on the commanded duty (0-100%) will determine the split between how long the pulse width stays at +12V versus 0V for each cycle. I'm just using +12 & 0 as nominal voltages here but think of it as high & low voltage depending on the application.
Currently in the wiring struggle on our 1/4 scale tractor. I think I've got a good handle on relays, but figured I can always learn more. This video is great, thanks Doug.
Nice video! I just finished my first relay project. I'm using two SPDT relays to turn off auxiliary power on my Dual Revolution lights when the turn signals flash. One controls the lights on the left and one for the right, they are wired as NC, and they are triggered by voltage going to the turn signal to cut the green light and allow them to be amber/red when the turn signal is illuminated and go back to green between blinks. It was fun to do, it's definitely an attention getter, and I was proud to get my idea completed, but I'm going to change it up slightly and add a strobe controller now.
I was working one with helping a friend who's a painter that said he is constantly blowing out his dual paint sprayer pumps. First thing I notice was his 100 ft extension cord 16 gauge & motors was so hot it would burn your hand😮 After buying the correct gauge extension cord 12 gauge he was good to go. He had a huge voyage drop. The lower your voltage goes the higher the amperes are the motor are toast😮
NOT POSITIVE , but I think what you meant to say was the LOWER YOUR RESISTANCE , THE HIGHER CURRENT FLOW .... thicker Guage wire has less resistance and is more CONDUCTIVE ....also the extension cords probably don't want to be EXCESSIVELY LONG .... only what 's necessary ....
Great info this is helping me as I'm building a engine harness from scratch, and I actually incorporated a relay fuse box on my harness. I added it for ecu, accessory and fuel pump.
Some things to take into consideration: Length of wire in a circuit includes + and -. Remember when calculating voltage drop. Design each circuit for 25% additional load over the fuse or circuit breaker rating. Avoid any high amperage equipment in the passenger area. I strongly recommend GXL or SXL crosslink polyethylene coated wires. Use IP67 rated enclosures for your components rather than that marine grade crap which offers little to no dust or moisture protection. Prewired relay sockets force you to use wires that are all the same colors which hinders repair. 87A is on DPDT relays. It is had never been used in SPDT relays. DPDT relays may be rare to you but they are not rare at all. Often used in interlock systems where you want to shut something off when another is switched on. Relays and be bought with a resister or diode on the coil circuit to protect electronics from surges. Micro relays can switch up to 40 amps and use the metric 280 configuration blades, terminals, and spacing. Amazing space savings can be achieved. High power relays are great for switching loads of 100 amps but, the safest way to wire the system is to go directly to the starter motor through a battery switch like a Cole-Hersey M750 and then take power from the starter for your system. This not only will keep maximum loads off of electronics but, will allow you to crank the engine without energizing anything else for compression checks, etc. I learned some hard lessons about automotive wiring in 50+ years since 1972 when I first got into drag racing. Got out of racing but have been in the industry one way or another my entire career in manufacturing and dealer support. Just retired last year so I actually have time to watch videos on the subject (I had no desire to "entertain" myself on off time with work related stuff). I thought your presentation was much better than most I watch. Obviously I don't totally agree but certainly enjoyed a video on the subject that didn't make me laugh. Anyway, I hope you are keeping up your good work as I see this post is four years old. I'll bet you have learned a lot since you posted this. I was learning new things even as I retired and I loved every minute of it. Did you know that 3M did a white paper on electrical tape flagging? I found it to be a good read, believe it or not. Checkout the 280 footprint stuff. It is actually very cost effective. You can pick out an IP rated enclosure that is an open grid. Then you can populate the enclosure with any 280 component like, fuses, relays, jumpers, etc. I used to make a 3.33" x 4.44" load center that contained 10 fuses (or circuit breakers), 5 relays at 30 amps, all of the seals, terminals, cavity plugs, brackets, with 10' wires for each input and output of the correct size if GXL wire for a total cost of $73.72. The finished product was IP67 rated and could be power washed. It took about 30 minutes to assemble on a normal day. If I didn't need all ten circuits, no problem. If I needed more I also had made up some two circuit relay block and five circuit fuse blocks in advance. Since I already knew what basic circuits I would be using regularly, most of the wire I used as function coded every 6" with its name and number. The additional price for that is included in the cost I gave. Be advised, there is a big learning curve involved with this method but, if you are going to be doing it for a living, your reputation is on the line with each and every thing you do so do it right. It will make the next major advancement that much easier.
Spot on! Get them relays as close as you can to whatever your powering up👍🏻 It’s definitely nice to have nice long pig tails for the relays my old relays had fuses in the power feed.. they do have 100amp relays that you can wiring in as key on or key off definitely I nice option 👍🏻👍🏻👍🏻
Iv'e used the fifth pin on a 5 pin relay to trigger a warning on the dash for a car that had a remote battery cutoff switch. The cutoff switch would drain power if you didn't hit the remote switch to disconnect the battery. I put a flashing light on the dash so when you turn the ign key off the light would flash telling you the battery is still connected and to hit the switch to disconnect the battery. But once you turned the ign key on the flashing light would go out. Was pretty cool to figure out a use for the fifth pin even if it was rare.
Thanks for the great videos. Very informative. I could never understand what a relay was, but you explain it so well. I will use this relay for my fuel pump when I install my EFI while I consult your other videos.
Excellent Video, I needed a refresh on car wiring specifically my electric fan set up and FI system. Exactly what I needed for the next steps on my 1970 442 revival after sitting in my garage since 2005. Feel free to send donations lol
Very good... Your explanation is the best so far. At first I was thinking your wrong about 16;02 . But as I got to listen to you more, ok,,, the other videos I was listening to are wrong. Yours is right.
Thank you so much. This information would have solved the issue I had with supercharger m3. The secondary pump wire kept getting hot, until it eventually made the connection fail multiple times. Looking back, it was 100% because of the thin gauge wire that was supplied in my kit. I do miss that that high revving v8 sometimes, but it doesn’t hold a candle to the smiles per gallon I get with my manual hellcat.
Always use the same size wire if not 2 gauge sizes bigger, depending on your applications and distance between the relay and the battery..... d/c and a/c currents only have one thing in common, they both flow outside the wire not through it.... but thats a different story for a different time..... just like anything, resistance in an electrical system is bad there has to be some sort of balance..... the better the balance the less heat you are gonna generate the more resistance you have the more heat you tend to generate...... so much that, like he says in the video, eventually the wires can't feed or hold the capacity of said or required voltage, either blowing the fuse or causing a fire from melt down of an overloaded circuit..... also, the same goes for grounding situations..... one of the most commonly overlooked things is grounds...... the shorter and bigger the ground, the better and more solid connection will be for your systems..... one thing I've always believed in personally for my own self is always run a ground cable one or three sizes bigger that your positive leads that is required for your system if there's not a place to ground to in a short amount of distance...... last but not least..... soldering is a must for any high-end electrical system the less connections in the circuit the better and less resistance you will have..... in some instances if you wanna use crimp connections.... dont... those are for lazy people that do shit half assed or in emergency situations just to get themselves going in a pinch..... not mention they look like shit......or sometimes its the only thing folks have to get things done..... sometimes beggers cant be choosers..... remember the rules.....measure twice cut once.... do everything right the first time so you ain't sitting on the side of the road at 3am wishing you done it right from the beginning...... 😉 🤙✌
@@cbd4734 diode is a means to unload the magnetic field in the relay coil. When power is disconected from the coil (control) then there is an inductive charge within that coil. If no diode is placed across the coil then you could have upwards of potentially 500v+. Not a big deal if straight to ground, but if the circuit is controled by a transistor/logic circuit then BOOOOOOM! Best practice is to use a diode. IN4001 is just fine between the +ve and -ve of the relay control coil. (Point the diode from -ve ->| +ve.)
@cbd4734 A diode can be compared to a check valve or a one way street. It will allow current to pass in one direction but not the other. Looking at it on a diagram the arrow points in the direction the current flows. Looks similar to this. ->|
Nope. I looked too. No link that I can find. He said he was going to add part #s too. They aren't hear either. I've found that is extremely common for RUclipsrs to say that they are putting info in the description and not do it. Very frustrating
Really cool video. I'm just starting to do some wiring on my project and I'm not very sure how all this works as a whole. You explained many of the questions that I had to begin with. You did very well in explaining why as well as how. I appreciate you taking the time to put info out to people like me. Thanks again and have a great day. My project is a 406 sbc powered ranger should be fun!
Very informative...quick question. If I'm wiring three different set of LED lights would I need 3 relays. If so, would each of them have a wire going from the 30 relay connector to + battery. Please advise. Thx. Or is there a different way to do this.
In my old muscle car at night when I would hit the brake I had voltage drop. since the wiring harness was good but it was outdated. I put relays on the back brake lights, headlights, dash lights. I also grounded the back brake lights, running lights, headlights with a heavier ground and additional ground. With relays I could cut the back brake lights off or on, tail lights off or on, and run the high beam and low beam both on at the same time for additional light since I was putting relays on everything. And hitting the brake pedal at night with everything going no voltage drop at all on gauge. Can stop the car in the road at night with no one seeing that the brake lights are on with the brake lights cut off and do a nice burnout or could street race.
Man thank you for showing how to properly wire a relay. I was watching some videos awhile back and come across a guy with a pretty successful channel and man he had it all wrong, wire the coil side straight to battery and ground, wtf. And wire on side to pcm and other to fuel pump. Omg. I quit watching and went to the comment section to see if anyone called him out on it and 1 guy did and that sob was so smug like yeah I don’t know what doing sarcastically, yeah buddy ya don’t, like you said he could cause someone to burn something down or fry a pcm, I hate idiots. You guys rock. Oh got my new flag hat from you guys and it’s awesome, I think my dog could smell y’all’s cause she was going nuts, or maybe all the freedom!
Thank you so much for explaining all these in details! I'm planning to make a fuel pump kill switch for my project car, and I was thinking about cutting off the power wire for the fuel pump to insert a kill switch. However, since you mentioned the voltage drop, I realized that increasing the length of the fuel pump wire might not be a good idea. I'll probably insert the kill switch in the wire that goes to 85 (probably the ignition switch?)
Just saw this nice information. Question! PWM signal. I have an Edelbrock Pro-Flo4. It has a fuel pump double lead. A negative and positive feed that plugs into a remote fuel cell that Edelbrock makes. Now, this can be used to trigger a relay. I fallow the schematic it triggers by the negative wire. The ecu has a PWM that can be turned on and off. How can this be wired up to a PWM fuel pump? The fuel pump has a 9 amp limit on it. Only #18 wire. Plus anything more is too much draw through the ecu.
**Plz plees help☆ How do i tie more length of wire to the short red/black+- stubs that come with the universal 12V electric pump ive bought? What gauge wire do they jineraly use? The two short wires coming with it are not long enough to connect to a 12 V auto battery i woud have placed a safer 8 to 10 feet from the tank. Trying to jrain out bad fuel-tainted gasoline from a 2000 pon-iak sunfire faster way than those dum flimzy hand pumps. Txs a million
I do industrial control engineering for a living and the turning point for me with relays was realizing they are just an electrically operated switch. In school we had always been told they were a way to control a large amount of current with a small amount of current, but that never made much sense. Once I figured out it was just a switch that you could open or close with electricity it got way easier.
Another question...regarding the relay...can I jump 87a to 87 to power my stereo even when the ignition key is off? I can power down the stereo manually. Hope that made sense.
Thanks for the detailed videos, really helps. Btw my girlfriend has a 2014 Hyundai Accent Sedan in mint shape but her front bumper is cracked, thinking about buying plastic welding sticks. Any idea what the plastic type is, TPO? or PP?
Love this video watched it a few months ago getting up to speed planning, now I have holley efi tank in, engine and trans in and starting with running all the fuel lines and wires ect.... I still dont know the best way to run the efi fuel lines past rear axle on my 70 gm abody 442 just looked at it tonight and factory line placements wont work..but car hasnt run since 05 and getting closer most every day
**Plz plees help☆ How do i tie more length of wire to the short red/black+- stubs that come with the universal 12V electric pump ive bought? What gauge wire do they jineraly use? The two short wires coming with it are not long enough to connect to a 12 V auto battery i woud have placed a safer 8 to 10 feet from the tank. Trying to jrain out bad fuel-tainted gasoline from a 2000 pon-iak sunfire faster way than those dum flimzy hand pumps
Very nice. My question is if there is power leakage or unstable power coming from the switch Will the relay compensate for the voltage and amp fluctuation?
Thanks , you are awesome But i always ask my self can i put voltage converter ( step down ) on 87 pin to make 12v step down to 6v form OEM car rear view camera ???
Yo did a great breakdown of all that. It is my first time ever even this and feel like I now have a much greater understanding and appreciation for the relays job. Than You
Can you explain how to wire this relay into the starting system? Bought a 66’ mustang that had this installed and removed it. They used the neutral safety switch wiring and the S terminal wiring for the starter solenoid.
At 14:00, it makes no sense to have a larger wire from the battery to the relay than from the relay to the device being powered. The current entering the relay is equal to the current leaving the relay (Kirchhoff’s first law). These wires should be the same size.
I have a side-by-side CanAm UTV with a 12V battery. There is a power distribution terminal under the dash that will energize when the ignition is on (there's a ground lug near by as well). Also, there are color coded wires passing through the firewall from this location directly to where the battery is located. I wish to provide power to my stereo, light bar, whip lights, back lights and rock lights via this power distribution terminal using rocker switches. My question is this...will this be too much for this terminal, and should I use an individual 30a or 40a relay for each device? Thanks in advance for your advice!!
Hi Doug , I’m putting in a gang switch box . How would I do a relay for this ? The box will be on the ceiling/ above the rear view mirror. 2 switches = KC Day Lighters then the other switches mainly led lights Where would I place the relay ?
So is the wire that is needed to be a larger gauge the red wire? This maybe why I’m not cooling. And is this wire the one from the relay to the battery?
Well, I subscribed because you seem to be an electrical Professor. Thanks for info. ? Can you tell me if a wire is ran from relay slot to inside fuse box to enable car to start? It was sold like this.
Relays are simple. I always do them this way 85 = trigger input. 86 = is the opposite of what you are using as a trigger. 87 = should be what you want as your output. 30 = your output. 85 and 86 are interchangeable, you can use 86 as your input trigger you will need to use the opposite on 85. If your trigger is negative (ground) then you will apply 12v to 86 (or 85 if you used 86 as your input). If you are needing 12V out of the relay (pin 30) then you will apply a FUSED 12v source on 87. SO if you have a negative input (85) and you want 12v out of the relay(30), then you would put a FUSED 12V on both 86 and 87.
So I have a c10 where I threw a lm7 in and I have now bought a cpp tank they don’t give u instructions on how to wire there fuel pump it came with a walbro intake pump to give me 60 psi I got the relay you sell but I need to know what is a good 12 volt switch to wire it to I got gauges wired to my light switch so where should I go from there also do I have to run a inline fuse this is my first time wiring
I was personally taught the opposite way to wire this. Not sure if there is a difference?? How I remember is whatever you want coming out of 30 you put on 87 (12v/ground) And whatever you use to trigger the relay (85) power or ground 86 is the opposite. So 12 volt switched output would be 87 12v batt 85 switched 12v (key on & crank) 86 ground 30 output. I've been doing it this way for year's.. is it not correct/same?? Serious question. Thanks great video!!!
You can do it either way. You can even put ground on 85 and your switch wire on 86. The coil doesn’t care as long as it sees 12v. just like the switching contacts don’t. Good question though. Some people can get confused on control voltage
Do you have a video explaining witch of the B&M and Holly automatic ratchet shifter is the best to use. I would like to find one that stays in one position when it ratchets threw the gears. Thank You
@cliff olsen **Plz plees help☆ How do i tie more length of wire to the short red/black+- stubs that come with the universal 12V electric pump ive bought? What gauge wire do they jineraly use? The two short wires coming with it are not long enough to connect to a 12 V auto battery i woud have placed a safer 8 to 10 feet from the tank. Trying to jrain out bad fuel-tainted gasoline from a 2000 pon-iak sunfire faster way than those dum flimzy hand pumps
Hey Doug, learned me some knowledge. I was using this MP 1050 double relay to power 2 fuel pumps, a 4303 as my secondary (hobbs switch controlled) and a smaller bosch pump as the primary for my turbo LS. So going to order another 1025 to run the smaller pump and wire the dual relays to feed only the big pump. My question though; throughout your video you keep saying 40 amp relay, but the 1050/1025 relays are actually listed as 30 amp relays. Did you just miss speak or are they listed incorrectly?
He touched on it about mid way through the vid. But most relays are 40amp on the NO (normally open) contacts and 30 on the NC (normally closed).In this case 30 to 87a is NC and 30 to 87 is NO. It’s also common practice (at least in years past) you can use a st85 solenoid. Which is a 80amp continuous duty solenoid that would be used like a starter solenoid on a ford etc. it is essentially the same as your standard relay just with a greater amp rating on the contacts and you only have 1 set of contacts. But super simple to wire. Your small studs would essentially be 86 and 85 on a standard relay and then your large studs one would be battery positive and the other is load side (device to receive power)
So you run thick wire from your battery and use relays, will a single battery and alternator be enough to run two fans and extra fuel pump and water pump by itself?
Some older cars have relatively low voltage in their system, hence, amperage running thorough the system. How would the relay be wired to maintain the amperage/voltage to a new-type distributor?
I have question: I am reworking my car old wire installation, so bow i am on headlights and rear lights. So i am wondering, can i putrear lights with hugh beam and low beam with seperate rrlays so ehen i turn lights i have rear also on one switch or need something different?!
What’s the best way to tie into the factory key switch? A) To retain the factory power distribution, and B) to activate a key on12V distribution block from the main cutoff switch with say, a 2 or 4 gauge wire feed? Thank you!
Most vehicles have an open (unused) power on when ignition switch is on terminal. Mount your relay as close to the component as possible so the heavy gauge (2 or gauge wire) are short (thus allowing the most amperage). The "trigger" line, in this case the 85 pin can be any gauge you want, it's not providing current, only a trigger voltage.
yes. 3 wire sensors can be split. pressure transducers at least for sure.. don't think you can split 2 wire temp sensors.. been trying to figure out a way to do that.
This young man has his "stuff"laced up tight. He's good at what he does and doesn't mind teaching others who are not as well informed.
Literally the best video on this I've ever seen. Currently wiring my truck, already knew how to use and wire a relay, but this video was great.
such an underrated channel! thank you for that, very nice!
After many years of learning and using relays wrong. This video made everything very clear.
Mate thank you, you are a legend. I have always get confused with relays but the way you explained it has now been implanted into my head and no longer have an issue. Champion! thanks again
These Tech Tuesday’s are the BEST. Relays always challenge me a bit. Thank you for this Doug!
Thank you for clearing up this issue for me Doug. I’ve been dreading a wiring problem for a little too long because the relays and wiring were pretty intimidating. But this clears up a lot of things for me.
The wire gauge vs. length is key. Previouslyr I didn't know that you can get away with a smaller gauge wire over a short distance. Those Derale fans come with small short wires - and people would think, 'I just match that gauge' to run the wire to where you need to go, but in my measuring I needed a larger gauge. Maybe why a lot of people complain of their electric fans not flowing enough or prematurely failing.
Your built in light location is awesome!
What gauge wire did you use on the derale fans?
@@BALLERXD24 8 gauge copper stranded wire. If you search the web for 12v wire gauge distance voltage drop - you can calculate the specs needed for your application.
8 Guage is large wire. Like for a starter. You mean a # 8 wire?
@@MichiganRay Sorry about that. Not sure why I typed 8. I ran 10 awg from the fans to the fan controller and battery junction. I like run 4 awg to my starter which I'm sure is overkill but I assume 200amps.
But yes, you can't trust anything on the internet these days. 😅
??????? WHERE ARE THE LINKS YOU SAID YOU WOULD ADD. ??????
Worth noting the electro magnetic coil contacts are interchangeable. 85 & 86, either can be ground or active
BY FAR, BEST VIDEO YOU WILL FIND ON RELAYS--TYPE, FUNCTION AND WIRING!
This young man clearly knows his stuff..It's always been a dark art to me, but this does shed some light on it..Thank you..UK
Ditto
awesome video and explanation of how to properly use relays to cure voltage drop problems. Thank you!!!
Great info... the MSD 7564 solid state relays are great compact and easy to wire. 4 in 1 relay
Who has the guts to even dislike this video? Man those tips are the best thanks motion raceworks
Just to clarify what you said about PWM, it doesn't exactly give you different voltages but instead gives you different duties. So for instance it will continually cycle from +12V to 0V hundreds or thousands of times per second and based on the commanded duty (0-100%) will determine the split between how long the pulse width stays at +12V versus 0V for each cycle. I'm just using +12 & 0 as nominal voltages here but think of it as high & low voltage depending on the application.
Currently in the wiring struggle on our 1/4 scale tractor. I think I've got a good handle on relays, but figured I can always learn more. This video is great, thanks Doug.
Nice video! I just finished my first relay project. I'm using two SPDT relays to turn off auxiliary power on my Dual Revolution lights when the turn signals flash. One controls the lights on the left and one for the right, they are wired as NC, and they are triggered by voltage going to the turn signal to cut the green light and allow them to be amber/red when the turn signal is illuminated and go back to green between blinks. It was fun to do, it's definitely an attention getter, and I was proud to get my idea completed, but I'm going to change it up slightly and add a strobe controller now.
Your best tech tip Tuesday thx 🙏🏻 so much.
I was working one with helping a friend who's a painter that said he is constantly blowing out his dual paint sprayer pumps. First thing I notice was his 100 ft extension cord 16 gauge & motors was so hot it would burn your hand😮
After buying the correct gauge extension cord 12 gauge he was good to go. He had a huge voyage drop. The lower your voltage goes the higher the amperes are the motor are toast😮
THANKS , ONE !!!!
NOT POSITIVE , but I think what you meant to say was the LOWER YOUR RESISTANCE , THE HIGHER CURRENT FLOW .... thicker Guage wire has less resistance and is more CONDUCTIVE ....also the extension cords probably don't want to be EXCESSIVELY LONG .... only what 's necessary ....
Great info this is helping me as I'm building a engine harness from scratch, and I actually incorporated a relay fuse box on my harness. I added it for ecu, accessory and fuel pump.
Thanks for a nice, straight-forward video, Doug.
Some things to take into consideration:
Length of wire in a circuit includes + and -. Remember when calculating voltage drop.
Design each circuit for 25% additional load over the fuse or circuit breaker rating.
Avoid any high amperage equipment in the passenger area.
I strongly recommend GXL or SXL crosslink polyethylene coated wires.
Use IP67 rated enclosures for your components rather than that marine grade crap which offers little to no dust or moisture protection.
Prewired relay sockets force you to use wires that are all the same colors which hinders repair.
87A is on DPDT relays. It is had never been used in SPDT relays. DPDT relays may be rare to you but they are not rare at all. Often used in interlock systems where you want to shut something off when another is switched on.
Relays and be bought with a resister or diode on the coil circuit to protect electronics from surges.
Micro relays can switch up to 40 amps and use the metric 280 configuration blades, terminals, and spacing. Amazing space savings can be achieved.
High power relays are great for switching loads of 100 amps but, the safest way to wire the system is to go directly to the starter motor through a battery switch like a Cole-Hersey M750 and then take power from the starter for your system. This not only will keep maximum loads off of electronics but, will allow you to crank the engine without energizing anything else for compression checks, etc.
I learned some hard lessons about automotive wiring in 50+ years since 1972 when I first got into drag racing. Got out of racing but have been in the industry one way or another my entire career in manufacturing and dealer support. Just retired last year so I actually have time to watch videos on the subject (I had no desire to "entertain" myself on off time with work related stuff). I thought your presentation was much better than most I watch. Obviously I don't totally agree but certainly enjoyed a video on the subject that didn't make me laugh.
Anyway, I hope you are keeping up your good work as I see this post is four years old. I'll bet you have learned a lot since you posted this. I was learning new things even as I retired and I loved every minute of it.
Did you know that 3M did a white paper on electrical tape flagging? I found it to be a good read, believe it or not.
Checkout the 280 footprint stuff. It is actually very cost effective. You can pick out an IP rated enclosure that is an open grid. Then you can populate the enclosure with any 280 component like, fuses, relays, jumpers, etc.
I used to make a 3.33" x 4.44" load center that contained 10 fuses (or circuit breakers), 5 relays at 30 amps, all of the seals, terminals, cavity plugs, brackets, with 10' wires for each input and output of the correct size if GXL wire for a total cost of $73.72. The finished product was IP67 rated and could be power washed. It took about 30 minutes to assemble on a normal day. If I didn't need all ten circuits, no problem. If I needed more I also had made up some two circuit relay block and five circuit fuse blocks in advance. Since I already knew what basic circuits I would be using regularly, most of the wire I used as function coded every 6" with its name and number. The additional price for that is included in the cost I gave. Be advised, there is a big learning curve involved with this method but, if you are going to be doing it for a living, your reputation is on the line with each and every thing you do so do it right. It will make the next major advancement that much easier.
finally really understand relays!!! Thanks for the explanation for us simple folks!! You got my sub!!
Very good and informative. I now truly understand how relay works.Thank you
Spot on! Get them relays as close as you can to whatever your powering up👍🏻
It’s definitely nice to have nice long pig tails for the relays my old relays had fuses in the power feed..
they do have 100amp relays that you can wiring in as key on or key off definitely I nice option 👍🏻👍🏻👍🏻
this was VERY helpful, wiring can be very intimidating and this made a big chunk of it make sense. thanks guys!
Iv'e used the fifth pin on a 5 pin relay to trigger a warning on the dash for a car that had a remote battery cutoff switch. The cutoff switch would drain power if you didn't hit the remote switch to disconnect the battery. I put a flashing light on the dash so when you turn the ign key off the light would flash telling you the battery is still connected and to hit the switch to disconnect the battery. But once you turned the ign key on the flashing light would go out. Was pretty cool to figure out a use for the fifth pin even if it was rare.
Thanks very much mate, explanations were great, you have helped me understand how to wire my project, greatly appreciated. Ken from Australia.
Thanks for the great videos. Very informative. I could never understand what a relay was, but you explain it so well. I will use this relay for my fuel pump when I install my EFI while I consult your other videos.
Excellent Video, I needed a refresh on car wiring specifically my electric fan set up and FI system. Exactly what I needed for the next steps on my 1970 442 revival after sitting in my garage since 2005. Feel free to send donations lol
Thank you for this. It is a great help. Learned a lot. If I run 2 fans is on relay enough?
Very good... Your explanation is the best so far. At first I was thinking your wrong about 16;02 . But as I got to listen to you more, ok,,, the other videos I was listening to are wrong. Yours is right.
Thank you so much. This information would have solved the issue I had with supercharger m3.
The secondary pump wire kept getting hot, until it eventually made the connection fail multiple times. Looking back, it was 100% because of the thin gauge wire that was supplied in my kit.
I do miss that that high revving v8 sometimes, but it doesn’t hold a candle to the smiles per gallon I get with my manual hellcat.
Very good lecture. I really appreciate the info that you shared. Thank you so much.
Thanks for the vid, very informative. Answered a few questions I had concerning wiring up a couple halogens on a pontoon build using relay a relay.
This is going to help me big time on my 1969 Nova.
It would help also if you could mention the recommended wire cross sectional area to amperage usage so guys use the correct wire gauge.
Always use the same size wire if not 2 gauge sizes bigger, depending on your applications and distance between the relay and the battery..... d/c and a/c currents only have one thing in common, they both flow outside the wire not through it.... but thats a different story for a different time..... just like anything, resistance in an electrical system is bad there has to be some sort of balance..... the better the balance the less heat you are gonna generate the more resistance you have the more heat you tend to generate...... so much that, like he says in the video, eventually the wires can't feed or hold the capacity of said or required voltage, either blowing the fuse or causing a fire from melt down of an overloaded circuit..... also, the same goes for grounding situations..... one of the most commonly overlooked things is grounds...... the shorter and bigger the ground, the better and more solid connection will be for your systems..... one thing I've always believed in personally for my own self is always run a ground cable one or three sizes bigger that your positive leads that is required for your system if there's not a place to ground to in a short amount of distance...... last but not least..... soldering is a must for any high-end electrical system the less connections in the circuit the better and less resistance you will have..... in some instances if you wanna use crimp connections.... dont... those are for lazy people that do shit half assed or in emergency situations just to get themselves going in a pinch..... not mention they look like shit......or sometimes its the only thing folks have to get things done..... sometimes beggers cant be choosers..... remember the rules.....measure twice cut once.... do everything right the first time so you ain't sitting on the side of the road at 3am wishing you done it right from the beginning...... 😉 🤙✌
Well put. I play with relays all the time. And I still learned something. Thanks...
If you have a diode suppressed relay, you must ground pin 85 and hook power to pin 86 to energize the relay.
The relay I bought shows ground pin is 85 so I guess I have a diode suppressed relay. But what is a diode/what does it do?
@@cbd4734 diode is a means to unload the magnetic field in the relay coil. When power is disconected from the coil (control) then there is an inductive charge within that coil. If no diode is placed across the coil then you could have upwards of potentially 500v+. Not a big deal if straight to ground, but if the circuit is controled by a transistor/logic circuit then BOOOOOOM! Best practice is to use a diode. IN4001 is just fine between the +ve and -ve of the relay control coil. (Point the diode from -ve ->| +ve.)
@cbd4734 A diode can be compared to a check valve or a one way street. It will allow current to pass in one direction but not the other. Looking at it on a diagram the arrow points in the direction the current flows. Looks similar to this. ->|
Good explanation Doug
Great knowledge for the enthusiasts, Thank you.
Has anyone been able to find the links he was talking about adding to the comments
Nope. I looked too. No link that I can find. He said he was going to add part #s too. They aren't hear either. I've found that is extremely common for RUclipsrs to say that they are putting info in the description and not do it. Very frustrating
You have to push "more" in the description, and in this video you have to push it again. Forget it. They are not there.
They’re there.
Really cool video. I'm just starting to do some wiring on my project and I'm not very sure how all this works as a whole. You explained many of the questions that I had to begin with. You did very well in explaining why as well as how. I appreciate you taking the time to put info out to people like me. Thanks again and have a great day. My project is a 406 sbc powered ranger should be fun!
That was really a good explanation of what I wanted to do. Thanks
Good knowledge!
I'll probably buy a 40 amp relay with a pigtail to learn more how electronic specs work.
Very informative...quick question. If I'm wiring three different set of LED lights would I need 3 relays. If so, would each of them have a wire going from the 30 relay connector to + battery. Please advise. Thx. Or is there a different way to do this.
very well done video!! to clarify, you'd want to wire the relay close to the device you are powering? did i get that right?
Awesome video man, Doug does a great job breaking it down Barney style for people like me🤣
😂 Thanks for watching!
@@MotionRaceworksOfficial How about adding the links and part #s you said you would?
In my old muscle car at night when I would hit the brake I had voltage drop. since the wiring harness was good but it was outdated. I put relays on the back brake lights, headlights, dash lights. I also grounded the back brake lights, running lights, headlights with a heavier ground and additional ground. With relays I could cut the back brake lights off or on, tail lights off or on, and run the high beam and low beam both on at the same time for additional light since I was putting relays on everything. And hitting the brake pedal at night with everything going no voltage drop at all on gauge. Can stop the car in the road at night with no one seeing that the brake lights are on with the brake lights cut off and do a nice burnout or could street race.
Man thank you for showing how to properly wire a relay. I was watching some videos awhile back and come across a guy with a pretty successful channel and man he had it all wrong, wire the coil side straight to battery and ground, wtf. And wire on side to pcm and other to fuel pump. Omg. I quit watching and went to the comment section to see if anyone called him out on it and 1 guy did and that sob was so smug like yeah I don’t know what doing sarcastically, yeah buddy ya don’t, like you said he could cause someone to burn something down or fry a pcm, I hate idiots. You guys rock. Oh got my new flag hat from you guys and it’s awesome, I think my dog could smell y’all’s cause she was going nuts, or maybe all the freedom!
Thank you so much for explaining all these in details! I'm planning to make a fuel pump kill switch for my project car, and I was thinking about cutting off the power wire for the fuel pump to insert a kill switch. However, since you mentioned the voltage drop, I realized that increasing the length of the fuel pump wire might not be a good idea. I'll probably insert the kill switch in the wire that goes to 85 (probably the ignition switch?)
Link to the diagram you spoke of?
Just type "4-5 pin relay schematic" in your favorite search engine
@@laneeric Good info but that's not the link or part #'s they promised.
@@ToddKing If you can't decipher a simple 4 or 5 pin relay then maybe electrical wiring isn't for you. It's very simple.
12 volt ninja! Great info guys
Awesome educational video. Really well explained.
verry helpful info about relays now i can wire up this electric fan correctly .... thanks bro
Just saw this nice information. Question! PWM signal. I have an Edelbrock Pro-Flo4. It has a fuel pump double lead. A negative and positive feed that plugs into a remote fuel cell that Edelbrock makes. Now, this can be used to trigger a relay. I fallow the schematic it triggers by the negative wire. The ecu has a PWM that can be turned on and off. How can this be wired up to a PWM fuel pump? The fuel pump has a 9 amp limit on it. Only #18 wire. Plus anything more is too much draw through the ecu.
Great video. Appreciated the discussion and the appropriate uses for it.
**Plz plees help☆
How do i tie more length of wire to the short red/black+- stubs that come with the universal 12V electric pump ive bought? What gauge wire do they jineraly use? The two short wires coming with it are not long enough to connect to a 12 V auto battery i woud have placed a safer 8 to 10 feet from the tank. Trying to jrain out bad fuel-tainted gasoline from a 2000 pon-iak sunfire faster way than those dum flimzy hand pumps. Txs a million
Where are the links? Great video but was disappointed at the end when I went to look for the links you spoke about..
Me too. Very frustrating.
I do industrial control engineering for a living and the turning point for me with relays was realizing they are just an electrically operated switch. In school we had always been told they were a way to control a large amount of current with a small amount of current, but that never made much sense. Once I figured out it was just a switch that you could open or close with electricity it got way easier.
SilentNight1647 exactly! It seems daunting til you realize that
Another question...regarding the relay...can I jump 87a to 87 to power my stereo even when the ignition key is off? I can power down the stereo manually. Hope that made sense.
Thank you for the knowledge simplification.
Thanks for the detailed videos, really helps. Btw my girlfriend has a 2014 Hyundai Accent Sedan in mint shape but her front bumper is cracked, thinking about buying plastic welding sticks. Any idea what the plastic type is, TPO? or PP?
Love this video watched it a few months ago getting up to speed planning, now I have holley efi tank in, engine and trans in and starting with running all the fuel lines and wires ect.... I still dont know the best way to run the efi fuel lines past rear axle on my 70 gm abody 442 just looked at it tonight and factory line placements wont work..but car hasnt run since 05 and getting closer most every day
**Plz plees help☆
How do i tie more length of wire to the short red/black+- stubs that come with the universal 12V electric pump ive bought? What gauge wire do they jineraly use? The two short wires coming with it are not long enough to connect to a 12 V auto battery i woud have placed a safer 8 to 10 feet from the tank. Trying to jrain out bad fuel-tainted gasoline from a 2000 pon-iak sunfire faster way than those dum flimzy hand pumps
Very nice. My question is if there is power leakage or unstable power coming from the switch Will the relay compensate for the voltage and amp fluctuation?
Thanks , you are awesome
But i always ask my self can i put voltage converter ( step down ) on 87 pin to make 12v step down to 6v form OEM car rear view camera ???
Yo did a great breakdown of all that. It is my first time ever even this and feel like I now have a much greater understanding and appreciation for the relays job.
Than You
I was under the impression runnig the solonoid closet ti the fuel pimp, fan etc was the best wat to go?
Can you explain how to wire this relay into the starting system? Bought a 66’ mustang that had this installed and removed it. They used the neutral safety switch wiring and the S terminal wiring for the starter solenoid.
At 14:00, it makes no sense to have a larger wire from the battery to the relay than from the relay to the device being powered. The current entering the relay is equal to the current leaving the relay (Kirchhoff’s first law). These wires should be the same size.
I have a side-by-side CanAm UTV with a 12V battery. There is a power distribution terminal under the dash that will energize when the ignition is on (there's a ground lug near by as well). Also, there are color coded wires passing through the firewall from this location directly to where the battery is located. I wish to provide power to my stereo, light bar, whip lights, back lights and rock lights via this power distribution terminal using rocker switches. My question is this...will this be too much for this terminal, and should I use an individual 30a or 40a relay for each device? Thanks in advance for your advice!!
Explained vary well thank you your help was great 100%.
I have a question, I did not see you mention a Spike Diode in there, is not necessary? Thanks..
Love this video thank you!
u are verygood explaining this thank you
what is the part number for the relay
Thanks for sharing this bro. You done Good
Hi Doug , I’m putting in a gang switch box . How would I do a relay for this ? The box will be on the ceiling/ above the rear view mirror. 2 switches = KC Day Lighters then the other switches mainly led lights
Where would I place the relay ?
So is the wire that is needed to be a larger gauge the red wire? This maybe why I’m not cooling. And is this wire the one from the relay to the battery?
Great vid.
Thanks!
Well, I subscribed because you seem to be an electrical Professor. Thanks for info. ? Can you tell me if a wire is ran from relay slot to inside fuse box to enable car to start? It was sold like this.
87a works great for your home wire on your wiper blade motor
Relays are simple. I always do them this way 85 = trigger input. 86 = is the opposite of what you are using as a trigger. 87 = should be what you want as your output. 30 = your output. 85 and 86 are interchangeable, you can use 86 as your input trigger you will need to use the opposite on 85. If your trigger is negative (ground) then you will apply 12v to 86 (or 85 if you used 86 as your input). If you are needing 12V out of the relay (pin 30) then you will apply a FUSED 12v source on 87. SO if you have a negative input (85) and you want 12v out of the relay(30), then you would put a FUSED 12V on both 86 and 87.
Another good video thanks 👍
So I have a c10 where I threw a lm7 in and I have now bought a cpp tank they don’t give u instructions on how to wire there fuel pump it came with a walbro intake pump to give me 60 psi I got the relay you sell but I need to know what is a good 12 volt switch to wire it to I got gauges wired to my light switch so where should I go from there also do I have to run a inline fuse this is my first time wiring
The guy that wired a fan switch in my car needs to watch this. Melted the fucking thing!
I was personally taught the opposite way to wire this. Not sure if there is a difference??
How I remember is whatever you want coming out of 30 you put on 87 (12v/ground)
And whatever you use to trigger the relay (85) power or ground 86 is the opposite.
So 12 volt switched output would be
87 12v batt
85 switched 12v (key on & crank)
86 ground
30 output.
I've been doing it this way for year's.. is it not correct/same?? Serious question. Thanks great video!!!
You can do it either way. You can even put ground on 85 and your switch wire on 86. The coil doesn’t care as long as it sees 12v. just like the switching contacts don’t. Good question though. Some people can get confused on control voltage
Can i run a physical switch on the 85 or 86 and why would you use a switch on one side or the other to complete the circuit?
Every diagram I see on line has the 85 as the ground ?
Do you have a video explaining witch of the B&M and Holly automatic ratchet shifter is the best to use. I would like to find one that stays in one position when it ratchets threw the gears. Thank You
@cliff olsen
**Plz plees help☆
How do i tie more length of wire to the short red/black+- stubs that come with the universal 12V electric pump ive bought? What gauge wire do they jineraly use? The two short wires coming with it are not long enough to connect to a 12 V auto battery i woud have placed a safer 8 to 10 feet from the tank. Trying to jrain out bad fuel-tainted gasoline from a 2000 pon-iak sunfire faster way than those dum flimzy hand pumps
@@rezagrans1296 that fed is not on topic. cut then paste your comment inti "Add a public comment"
Hey Doug, learned me some knowledge. I was using this MP 1050 double relay to power 2 fuel pumps, a 4303 as my secondary (hobbs switch controlled) and a smaller bosch pump as the primary for my turbo LS. So going to order another 1025 to run the smaller pump and wire the dual relays to feed only the big pump. My question though; throughout your video you keep saying 40 amp relay, but the 1050/1025 relays are actually listed as 30 amp relays. Did you just miss speak or are they listed incorrectly?
He touched on it about mid way through the vid. But most relays are 40amp on the NO (normally open) contacts and 30 on the NC (normally closed).In this case 30 to 87a is NC and 30 to 87 is NO. It’s also common practice (at least in years past) you can use a st85 solenoid. Which is a 80amp continuous duty solenoid that would be used like a starter solenoid on a ford etc. it is essentially the same as your standard relay just with a greater amp rating on the contacts and you only have 1 set of contacts. But super simple to wire. Your small studs would essentially be 86 and 85 on a standard relay and then your large studs one would be battery positive and the other is load side (device to receive power)
great explanation! thanks!
So you run thick wire from your battery and use relays, will a single battery and alternator be enough to run two fans and extra fuel pump and water pump by itself?
Great video, thanks
Some older cars have relatively low voltage in their system, hence, amperage running thorough the system. How would the relay be wired to maintain the amperage/voltage to a new-type distributor?
I have question: I am reworking my car old wire installation, so bow i am on headlights and rear lights.
So i am wondering, can i putrear lights with hugh beam and low beam with seperate rrlays so ehen i turn lights i have rear also on one switch or need something different?!
I'm going to tune out but at least you're not saying relays make more power like some RUclipsrs
What’s the best way to tie into the factory key switch? A) To retain the factory power distribution, and B) to activate a key on12V distribution block from the main cutoff switch with say, a 2 or 4 gauge wire feed? Thank you!
Most vehicles have an open (unused) power on when ignition switch is on terminal. Mount your relay as close to the component as possible so the heavy gauge (2 or gauge wire) are short (thus allowing the most amperage). The "trigger" line, in this case the 85 pin can be any gauge you want, it's not providing current, only a trigger voltage.
Can you split a oil pressure sensor one for terminator x and one to gauge.
yes. 3 wire sensors can be split. pressure transducers at least for sure.. don't think you can split 2 wire temp sensors.. been trying to figure out a way to do that.
I only watched because you do Cleetus content. Thanks for the Bald eagles