Wiring an AC compressor relay

[@elijahvertsehovski7020]

Thank you sir! One of the most informative videos on KZbin. That in fact can save people thousands of dollars on trying to figure out what went wrong with their AC and anything else. If you can rewire then do it! This way you actually will know how it works and will help with possible future repairs. I’m working on my Freightliner Cascadia. And when I connect new AC compressor it just burns clutch coil immediately. And this truck somehow has a lot of things controlled by the computer. So for me it’s easier to bypass it. And this video just helped a ton! Thank you again Giancarlo

[@Jvcomet]

Yes sir thanks for watching

[@jccui4916]

Amazing! I searched online two days about relay diagram, that’s the easiest way to understand how relay works! Great job!

[@Jvcomet]

Thanks glad it helped 👍

[@AmadorRt]

Does every car have a relay? Where does the Red wire go apart of the relay, is it the ignition coil?

[@Jvcomet]

@@AmadorRt to the on off switch

[@Shoeless_DA]

Troubleshooting my compressor. This was immensely helpful, thank you!

[@Jvcomet]

Thanks for watching 👍

[@Driftprodigy01]

Thanks man I've been getting a headache searching this up I have an ls subaru with a fitech standalone so I don't have a pcm but everyone uses the oem ls wiring 🤦‍♂️ this just saved me

[@Jvcomet]

That’s what originally wrote that up fir a buddy of mine that did a LS swap. In a ranger and wanted the ac to work. Glad it helped. Thanks for watching please subscribed and hit the like button for us. 👍

[@valdezerick]

I just do my ls swap on my 96 Sierra and with this video my a/c is back to work easy and cheap ! Thanks 😊 good bless you

[@Jvcomet]

Awesome glad it helped. Thanks for watching and hope you subscribed. 👍

[@laurencevillegarage]

Excellent and to the point, even I am able to understand this!! Thank you!

[@ronmeyer2308]

Doesn’t get any more simple than that, good job!

[@Jvcomet]

Thanks

[@JayJay-rm8ru]

Great video I've been researching how to instal ac to a non ac truck it's a 95 c1500 I'm fine with all the under the hood stuff but the wiring has been an issue this helps allot thank you

[@Jvcomet]

You’re welcome glad I could help you out don’t forget to like and subscribe for us appreciate you watching

[@davidpeterson4122]

This helped me a lot thank you ! I have a new 383 with a sanden pump trying to make all this work on a 73 Nova

[@Jvcomet]

Cool thanks for commenting👍.

[@jm-xy6xh]

Thanks so much!!! Just what I needed

[@crackshotmcgee9588]

Thanks a lot for the explanation. Have a no power situation to my ac clutch in my 04 dakota and jumping 30 to 87 does nothing but running power from the battery to the clutch does. Didn't have my meter with me today but obviously I need to find out where there is power and where there isn't. Didn't think of it then but should've jumped 30 from the ac plug to 87 on the wipers plug to verify if there was power there or not. 😊

[@Jvcomet]

Yep hope you figure it out

[@chrisuguni7841]

I loved to see more from you.

[@kjarby69]

Great informative video!👍 I appreciate it!

[@Jvcomet]

Thanks for watching hope you subscribed for us 👍

[@julesofsouthafrica9994]

Does the control circuit need a resistor to limit the current flowing from 12v through the switch and the relay and the lo & hi pressure switch to earth?

[@obedtusime181]

Thank you for a very instructive video. I would like to ask if a trinary pressure switch that is in most cases mounted on the ac receiver drier is perfect substitute of having two high and low pressure switches. I heard that you may have a single trinary switch and no need for high and low switches

[@Jvcomet]

Your welcome thanks for watching. Hope you subscribed . Thanks.

[@obedtusime181]

In addition to that, I would like to ask how can I wire this setup to the idle air control valve to compensate for the ac load?

[@Jvcomet]

@@obedtusime181 not sure but I remember back in the 80s cars there was a little electric solenoid that would kick the idle up might be able to find something and do it that way

[@W.Eric.Anderson]

outstanding!...Thank you!

[@TheUltimate65]

This its wel fore manually AC system , not all have swith fore low presure , but the are four types of highpresure swith one too four pinns

[@impactlifemastery3754]

Wooow!!! Very informative 👏

[@Jvcomet]

Thank you thanks for watching👍

[@impactlifemastery3754]

Please I have done a new a/c installation on ford fiesta 2014 but when I turn the a/c on the clutch doesn't engage. But when I bypass the a/c clutch relay it engage, please is there any help?

[@Jvcomet]

@impactlifemastery3754 would need to talk to you in person to get more info. Send me a message or call me.

[@albeaulieu9269]

Thanks for this video! I've been beating my brains out trying to get power to my compressor via instructions from Classic auto air. In short, your way works and theirs didn't

[@Jvcomet]

Lol. Thanks for the compliment. Hope you subscribed t the channel for support 👍👍

[@cooliecrewspeedshop]

Does the positive on the low pressure switch go to the negative or positive on the high pressure switch?

[@Jvcomet]

Negative both switches are ground .another words both switches complete the ground Circuit

[@NextGenWealthTips]

I know this is 4 years ago, but I am trying to spoof my car thinking the ac is on so I can have the idle and fans to run. Is there a way to just bypass the relay and just have a switch there tricking the car to run at the idle speeds as if the ac compressor was running?

[@Jvcomet]

I guess you can disconnect the compressor.

[@pappypulcinella886]

Giancarlo, please post more auto electric and race car wiring videos. I want to learn it all as much as I can....Grazie . Ohm's law...🤦🏻‍♂️

[@Jvcomet]

Sure thing . Thanks for watching

[@2slow2gs]

So do I wire a positive into the on/off switch so when it’s off it gets no power but when it’s on it gets power

[@Jvcomet]

Yes

[@joearevalo9881]

The voltage reading from the low side of my a/c switch connector is showing 4.7 Volts from one side wire and 13.6 V from the other wire on same connection, is that normal? Is not one side suppose to be grounded, or no power until switch is activated to engage a/c clutch?

[@Jvcomet]

Yes one should be ground. 🤔

[@hamzasaleem2901]

I have a trinary switch wired in on the high side of my system, one ground goes to my fan relay and the other I tied into the binary switch on the low side. My question is should I run the other 2 wires to the compressor and ac request circuit or does the trinary switch need its own relay?

[@Jvcomet]

Not sure on that one sorry

[@danhammer2690]

My 87 Monte is a wiring nightmare for ac now that it has been fully converted from fuel injection to carburetor. I can not get my ac to work and too many wires have been eliminated for me to trace this issue. My heat and blower motor and all that work but the ac does not engage. SO, following this set up, is there a way to wire aftermarket pressure switches with this wiring set up you show? If so, please explain. Thanks!

[@Jvcomet]

Wire it like in the diagram. Aftermarket pressure switches are the same.

[@chaminthaw]

Thank you sir, can you kindly let us know how to wire the condenser fan in to this as well

[@Jvcomet]

Wire it in line with the same wire that Powers the compressor,. The fan only needs to run when the AC is on

[@alexalex4423]

i just got a 2018 ram promaster and everything on the dashboard turns on exept the controls for the a/c there is no lights on the knobs. the relay is good the fuse is good .i got power on terminal 30 and when i turn on the switch i get power on terminal 85 but no lights on the dashboard a/c knobs. what do you think.

[@Jvcomet]

Not sure could very well be the knob itself 🤔

[@75bigwalk]

2000 Jeep Grand Cherokee Laredo the a/c pump has 2 wires so would I ground the one?

[@Jvcomet]

Yes or hook it the the house low switches to ground

[@MrRohanstar]

2019 hyundai kona ,pressure switch is 3 wires so computer fan ect

[@Jvcomet]

Yes should be.

[@johnwood7650]

Good video thanks

[@Jvcomet]

Your welcome. Glad it helped. Hope you subscribed. Thanks

[@terransettles5430]

Like button very informative 👍

[@Jvcomet]

Thanks. Hope you subscribed for us and thanks for watching 👍

[@gustavosantana853]

Question. So both pressure switches are wired together correct and 1 grounds .. do I tap into the existing power wire coming from the pressure switches? Or rewire ?

[@gustavosantana853]

Or is it a ground I’m connecting 86?

[@Jvcomet]

Yes it’s either a ground or to a pressure switch witch becomes grounded when it has pressure. Hope that helps 👍

[@Fjaydub]

How would you wire in an electric fan to this setup? I have an aftermarket single electric fan wired to a fan controller and a keyed switch. I just had a complete AC unit installed so I need to get that wired in so the fan turns on when I hit the AC switch inside the cab???

[@Jvcomet]

So first off you need a second relay just for the fan you would wire it the same as that other relay except there will be no high low switches

[@Jvcomet]

If you need to call me. 914-490-4306thanks for watching

[@urbanturbine]

Does it matter if 85 and 86 are swapped? Meaning would it till work if dash switch (12v positive) came to 86 and got grounded at 85 through the pressure switch(es)?

[@Jvcomet]

It might but not sure.

[@urbanturbine]

@@Jvcomet i just tested. It works both ways. Coil still pulls when current applied from either direction... Kinda interesting.

[@Jvcomet]

@@urbanturbine cool that’s good to know . Thanks for sharing and watching 👍

[@urbanturbine]

@@Jvcomet thank you for posting this video. İt was helpful for me.

[@davidpound2375]

I have a question how would I do it if I only have a pressure switch. This is on a 1987 mustang

[@destruct61]

I'm about to attempt this on a 2011 Honda CRV that got flooded The AC system is in perfect working order just the electrical side of it is not now with your help I'm just going to wire it up myself to a switch 🙂

[@Jvcomet]

Yep that should work. Thanks for watching

[@destruct61]

@@Jvcomet quick question my high pressure switch is a 3 wire I've got ground signal and reference do I just use the ground and signal and leave the reference unconnected?

[@Jvcomet]

Not sure on that one. Sorry may have to trial and error that one.

[@snowman6512]

my 1988 caprice came with just a low pressure switch by no high pressure switch, would i still be able to use the diagram you showed in the video?

[@Jvcomet]

Yep

[@snowman6512]

@@Jvcomet ohh ok. im running a r4 compressor could i put a high pressure switch into it? i seen that some models came with sensors on the compressor

[@Jvcomet]

I’m sure there’s a way to add one if you really want it.

[@snowman6512]

@@Jvcomet ok cool, thanks for the help

[@Jvcomet]

If it has 2 wires one is positive one is negative. ​@@JoseReyes-pl7td

[@jasveer8370]

Can you suggest me more videos this way diagram are you good tech thanks

[@Jvcomet]

There are tons of tech video’s on KZbin. Just search for what you need specifically. If there are any you need maybe I can make more. Thanks for watching 👍

[@dangerdavefreestyle]

Does this affect the idle at all? Such as when the compressor is running the idle will reduce from 600 to 400 or 500?

[@Jvcomet]

Yes when the compressor kicks on it’ll draw down on the engine another thing you can do is put a stepper solenoid next to the idle control if it’s a carburetor you can get a little electric solenoid and wired into that so that when the compressor kicks on it steps to idle up

[@davidb2542]

will this let the compressor cycle off and on

[@ChristianGomez-b6d]

I'm kina wounding the same thing I swong I head it cyle

[@Jvcomet]

What year make and model car you working on.

[@jesusdavila8641]

@@Jvcomet2003

[@jesusdavila8641]

@@Jvcometoriginal compressor on a jeep TJ 5.3 swap.

[@Jvcomet]

Yes compressor cycles when the pressure is reached high or low.

[@Icysoles60]

how would you do it, if you want to control the AC temp?

[@Jvcomet]

The relay set up will not control the actual temperature it’ll only control on off of the compressor

[@cristonsalandy965]

I want to do this to my 93 corolla because the ac module is bad and not getting good one to replace

[@Jvcomet]

Should be doable. Thanks for sharing

[@Jvcomet]

Let us know how you make out with it 👍

[@Sss-rj9ed]

Me I ask this wiring is applicable to computer or ecb unit

[@Jvcomet]

I would think so. 🤔

[@valsierodgers9269]

what about a binary pressure switch?

[@Jvcomet]

Good talking with you. Thanks for watching and subscribing 👍

[@reynardleveridge2098]

I need your help how can I contact you have some questions

[@Jvcomet]

914-490-4306

[@ChristianGomez-b6d]

Does this apply for any ac like Honda swap

[@Jvcomet]

Yea all the same.

[@ChristianGomez-b6d]

​@Jvcomet what if my 85 and 86 are in the opposite sidecause my 85 is on the left and 86 on the right

[@Jvcomet]

@user-bu6xj7xi6x should still work.

[@ChristianGomez-b6d]

I've noticed my car keeps ove heating when the ac is on new condenser new dryer I think the ac compressor is causing extra stain and causing it to overheat

[@ChristianGomez-b6d]

Ac works but starts to overheat

[@jameshead7780]

Great but what am.i looking for

[@Jvcomet]

??

[@doncarr5874]

Why not just run a hot wire to the compressor???

[@Jvcomet]

You can but if the system goes high or low you’ll fry the compressor

[@langstonwaller4724]

I’ve got my old kenworth wired up that way and it freezes up. Have to remember to flip that switch off to let it thaw out every 5 minutes. I’m gonna wire it this way to have a little better quality of life going down the road

[@Jvcomet]

@@langstonwaller4724 thanks for watching.

[@samansilva2584]

Were is the selector & thermostat wiring connections ,you wrong.

[@Jvcomet]

You can only control the on and off of the compressor with a relay.

[@doncarr5874]

where do you get the relay????

[@Jvcomet]

Any auto parts store will have the relay and the connector. Thanks for watching 👍