question for you guys that kept the R4 pancake compressor and a/c system. im doin a install on my buddies car and he decided for the time being to keep the R4 compressor. his PSI harness has a a/c request wire on it and i have all the plugs with a bit of pigtail on them. he is also running stock 4th gen fans if that helps any. looks like there is 2 plugs straight off the compressor, 1 plug/pressure sensor off one of the lines. i dont have the rest of the engine harness since it went with the motor when it got sold. i tried looking at schematics but just couldnt figure them out. i can get a pic of the pigtails etc..

any help is greatly appreciate since im almost done with this thing and just pretty much need that wiring and gauges. then it goes to exhaust and tune.

 

sorry been busy tryin to finish this thing up. anyways heres some pics of the wiring i need help trying to hook up. the PSI harness he has has a "A/C request" wire coming from it.

heres the pigtails and plugs i need help trying to tie into the LS harness and rest of the a/c system for it to work. again any help is appreciated since this is pretty much the last thing i need for this thing.

 

need to start with the year and engine he has. the ECM varies a bit I think and thus the wiring varies a bit. the front switch on the a compressor is the cut-off switch if pressure gets too high. don't have a wiring diagram handy at the moment, if you can post one can help tell what the others are. sitting down and understanding the diagrams will go a long way and getting your there. highly recomeneded !

 

Here is one example, the blue/green wires near the firewall gp to to the pressure switch on the hard line or the accumulator - maybe there are 2, again think this depends on year.. light blue dark green to the high press switch on compressor. the mysterious diode is hidden and wrapped up near the compressor.

 

yep, my 90 has 3 switches in total, one on accumulator, one on hard line, and the high press cut off

https://www.thirdgen.org/forums/cool...ml#post6313989

https://www.thirdgen.org/forums/cool...ml#post6314534

 

if you havent visited, good set of info over here. https://lt1swap.com/93lt1a4.htm

 

sorry i thoguht i put it but i guess not. his car is a 92 RS it had a 305 tbi in it. new setup is ls1 with a PSI harness.

i tried looking at the diagrams but just confused me more. i hate electrical. its something ive worked with forever but never grasped it. i always have to ask for help. hell anytime i wire a relay i have to look it up and even then its confusing cause it seems like there multiple different ways to hook those up.

i havent looked up lt1swap for this. i was looking at diagrams for the car on austinthirdgens.com. that diagram you shared looks like the same one they have for the 92

also thank you for the help. sorry if i sound dumb on this but like i said i hate electrical. my car was simple since i did a vintage air setup and my buddy had a simple wiring diagram for it eventhough there isnt much to hook up on those.

 

look at those links with photos I posted. you can see the color of the wires and where they go. if you are having to swap out an LS1 computer, then I'm not sure, but someone must have figured that out. not sure how much is a/c is controlled by an ls1 conputer

 

yeah thats kinda what im not sure about either. i know there is 1 wire they labeled off of the LS harness that says "A/C request" which from what i understand just sends 12v when the a/c controls gets power.