Last week I picked up a book on swapping an LS motor into a non LS car. Overall it was full of a bunch of generic crap that was of little use to me, but one thing that caught my attention was the a/c compressor information. According to this book, the stock 4th gen compressors won't work with our older systems because it's a PWM style compressor that will ultimately wind up on all the time with our old controls. It stated that you need an aftermarket Sanderson compressor that fits the 4th gen form factor, but utilizes the traditional on/off style clutch.

Anybody know of this, or is everybody just using the 4th gen compressor?

 

Doesn't sound right. Although I haven't gotten my system hosed up and charged yet, the "AC Request" wire getting 12 volts from the stock HVAC control should tell the PCM you want AC, and the PCM will take it from there.

You will need to use the LSx pressure switch, though.

 

https://www.thirdgen.org/forums/ltx-...ng-i-need.html

Check that thread out. Only difference is theres a diode near the compressor connector

 

Thanks.

 

I'm using the 3rd gen compressor on my swap with no issues

the lsx style compressor are much more efficent, just get the condensor to match

 

I am running the 4th gen compressor with factory controls with no issues. I am running ALL 3rd gen ac stuff, dryer, condensor, everything! The only thing differant is custom lines, and the 4th gen compressor. Ive got a few pics on my swap thread with the ac compressor.

https://www.thirdgen.org/forums/ltx-...-z28-swap.html