How To Wire An Automotive Relay 

Great information! Most young adults getting into basic skills like this need more videos to show how to do it.

Great video with step-by-step plus illustration. Best video I have seen on youtube. So clear instructions.

Best video I've seen explaing a simple relay. I used this video to help me put together and install a replacement Toyota Corolla horn and bypass the wiring clockspring switch horn connection and used the original horn which was still good.

great video..really clear

Most informative vid i ever seen about relays, many many thanks!

I was searching for information about the ground and positive in the relay with diode and this was the only video I watched that explained it.

Very informative and yet focused, thank you :)

Great video and a great education. I am just learning about the basics of automotive wiring.

THANK YOU FOR Sharing you knowledge!!!

Great Tips, Good Stuff 👍 Thanks! I didn't know about the A & B Relay and Standard Charts. 😄

Well explained

A video for many Terminator X (and other ECM) users on how to wire fans with a negative trigger would be good.

I wasn't going to watch this cause I wire relays all the time. Wow this was a lot of information! Thanks!

great presentation.

Awesome video. Thank you

Very detailed Thanks

Learning this stuff on my own trying to build my car great info

Great information. Thank you.

Should you use different grounding points for the relay, toggle switch, and accessory or can you ground all of them to the negative battery terminal? Thank you for your response.

I am now confident to do it my own. Love from PNG

Loved It!

Thank u sir its worked for me in 3wheeler autorikshaw. Love from india 🇮🇳

very helpful . tnx alot

I'm questioning what you said about the 85 and 86 connections of a diode protected relay. The DIN 72552 standard says that 85 should be connected to relay coil negative and 86 should be connected to relay coil positive with a specific note that this is important if the relay coil has a flyback diode in parallel. This is the opposite of what you said in this otherwise excellent video. It took me a while, using the second and third hand rules for current and magnetic fields, to figure out what the diode is actually doing when place in parallel with the relay coil. I initially thought that the diode was going to prevent a back current to the cathode. This is incorrect, but I believe it is what a lot of people think. What the diode does, is provide a low resistance loop for the current, that is induced when the magnetic field collapes, to flow around until the energy is dissipated. This protects any transistor or switch which is acting as the trigger for the relay. Since the current induced by the collapsing magnetic field is in the same direction as the original current, the diode needs to be connected with the cathode toward 86, which is how they are wired in a diode protected relay. Consequently, there is no need to change the way you connect a diode protected relay. 86 is still connected to switched positive and 85 is still connected to ground as the DIN 12552 protocol specifies.

GOOD LOOKING OUT

great video! btw, DIN is deutsche industrie norm, i.e. its not an automotive standard but a generic german industry standard. even pieces of paper fall under DIN in germany

If you’re interested in supplying power to your air solenoid valve which would be your terminal to activate the solenoid to open the air supply to brake line?

I'm looking to install some of those led running board strip lights and was thinking of having all the functions run off of rocker switches and relays instead of hacking into my headlight harness. My question is; if I get one of those relays with a left/right blinker function and rocker switch also with turn signal functions it should work if I wire everything up properly right? Are there any relays that by chance have a running light option and no turn signal for the other switch? Basically just looking to run the turn signals and running light functions that I can turn off and on from rocker switches instead of running them on the main vehicle lighting system I guess you could say. Looking to try something different

Would it b smart to put a big enough relay wen installing a audio system on a Harley to not kill the stator

Thanks for your explaination, mate, but just a quick question, how to connect 85 86 if I don't need a swith for control circurt ? just leave the 86 empty and connect 85 to ground ?

Totally get it. My issue is the relays are hardly ever clearly labeled.

Hi! I'd like to ask, what is the awg size of the coil's wire?

is it necessary to use a resistor or anything of the sort on the switch circuit, or is the electromagnet itself a "load"? Looking at the configuration, it almost looks like we are creating a short circuit with the switch.

Which relay would protect a car ECU better? With a diode or resistor?

I am using a ground switch on the 85 terminal, which means the electromagnet is always on. However the relay is now getting warm because it's on all the time, wouldn't that be dangerous ?

Thanks! This explained very well how and when 87A gets it power. I am connecting a buzzer that will sound when the fan are not turned on/ fuse to the fan breaks Cheers

I'm good with residential and automotive wiring, but like how do you figure out what relay to use when wiring a car when ever I had to fix something n if it was the relay I would just replace it with the same but for wiring a car from scratch how would I figure out what relay to use 🤔

Good morning

I have a weird setup of relays in my car which I'm struggling with. Anyway I can post a photo somewhere where you can see it?

my fuse box fan amp says 40 but im running manual switch to a 30 amp relay is that okay or should i put 40 amp relay

Great info. Thank you.

How come no one shows where the other wire to the switch goes.. If it goes straight to the battery how is the relay supposed to stop the switch from catching flame 🤔

Do I need to worry about back emf suppression?

Wish he would show the wires after they are hooked up

I want to add a kill switch to my 2021 Nissan NV 200 (small cargo van). I don't want to kill the battery because I want the security system to remain functional. So I thought a fuel pump relay kill switch would be good. However, auto shops around here won't do it...they say adding a kill switch would screw up the CAN bus. Scotty Kilmer (youtube guy) says the best way to prevent car theft is to just remove the fuel pump relay and take it with you. Sure, but that means I would need to open the hood, open the relay box, pull the fuel pump relay and take it with me...and when I get back, open the hood, put it back in. But I was thinking...would it be possible to relocate the fuel pump relay into the dashboard? Place an extender-type socket device, pass thru socket device, from the relay box in the engine compartment and run wires thru the firewall into the dashboard, to a pass thru socket which would accept the fuel pump relay? This way, I could just remove the fuel pump relay without having to open the hood, etc. There would be added distance that the signal would need to travel, say 6ft. But basically, I would have everything be a pass thru to the regular fuel pump relay which happens to be in the dashboard now. What do you think?

I install these things so fast all my buds say I should enter a relay race.

Show us instead how to use map based boost control on your terminator x system after you push the update out.

I have watched about 10 videos on how to wire a relay. And can’t understand it every time at this point considering an autism test.

hey hey simmer down

As

Not very well explained in my opinion I am still as stuck as when I first started

This is just an explanation of relays not a how to wire a relay

Or you could just look at the pretty picture on the side of every relay...SMH

That was useless