I've almost got my car wired, but had a question regarding the A/C clutch status wire. It's PCM connector 18 and goes to the LS1 C100 connector. Were does this wire go? I've got the A/C compressor wired and the relay set up. Also, the serial data wire goes to the ALDL connector correct?

 

A 411 PCM, serial data would be DK GRN and run from ALDL to Blue 58. Post #8
https://www.thirdgen.org/forums/ltx-...formation.html


The A/C, there are a few ways to do it. You gave too little information to answer specific to your application but your answer may lie in this thread.
https://www.thirdgen.org/forums/ltx-...ng-i-need.html

 

Thanks for shooting me in the right direction. I'm running the 4th gen A/C compressor with Hawks swap lines.

I'm attempting to wire this thing myself but I'm about ready to say screw it and order a Painless harness. I have all wires extended to run inside the car through the passenger side fender. The only issue I'm having is finding out exactly how to wire the fuse block and relays into the harness. I've read so much crap on here that I've confused myself to the point of tossing in the towel. Wiring just is not my thing... so close to fire this new motor up yet so far.

 

Don't give up, it's one of the most satisfactory parts.

 

I can tell you from experience that another wiring kit won't make it easier. You'll still have to solve all the same problems and more.

Wiring is certainly one of the bigger tasks. Your struggle is normal. Just keep asking well worded and well defined questions and you'll get the help you need.

 

Wiring is pretty straight-forward, really...




I tried to minimize harness modifications when I did my two LS1 swaps in 3rd gens. This pic is from my LS swap into a '57 Bel Air - got more into that one out of necessity. Some day I'll go back and do a better job on the LS1/4L60E in the '82 Berlinetta. For now, it works.

 

Just got done with mine a month or 2 ago and did the same setup with the 4th gen ac compressor. What specific questions do ya have with that or with what relays, Ill gladly help ya out. Sometimes you can overload and just need to reset once it clicks its not that bad. have done 2 other LS swap harnesses since my 3rd gen one for my buddies.

 

ok I need to ask, I also installed ls engine in my 90 iroc . I have all the wires hooked up as shown above but my 411 ecm will not send grd to relay to turn the ac compressor on. I can manually grd the relay and compressor comes on. Any ideas?

 

If running the F body compressor and OS, then you need a pressure sensor in the AC high pressure line from a 90's LT1 Fbody. The newer PCM uses a pressure sensor to replace hi/lo switches of older systems

 

I have the pressure sensor in place also, I even checked the grd that the ecm uses to bring the relay in when ac switch is turned on but the grd is not being sent for some reason. The ac system has not been deleted per hp tuner.