https://jp3motorsports.com/products/...ef8feb77&_ss=r

 

I thought I posted about this in this thread but maybe not. About 2020 I started having an issue with the compressor clutch engaging right after I started the car, whether the AC was on or not, but only when the AC wasn't charged, which is a huge problem in itself. This started when I noticed that AC wasn't working after the winter of 2019/2020. I assumed it had leaked out so I jumped the pressure switch and it the compressor clutch engaged. Once I removed the jumper, the clutch stayed engaged. Weird. I had already had some issues with the ECU, not realizing I had fried the water injection circuit already. After more troubleshooting, it seemed to me that the ECU was causing the issue, because the issue would go away if 1L (the output) was disconnected, but even if 1E (the input/request) was disconnected, the issue remained. So basically even if the ECU wasn't being told to turn on AC, it would turn it on. I also checked 1L to verify it wasn't grounding somewhere.

Last winter I rebuilt two of the compressors I have, and I replaced the expansion valve and cleaned the evaporator, which wasn't all that dirty. I replaced the condenser again to start fresh, and flushed all the lines and tested anything I could test within the circuit, aside from the AC button itself. And since my ECU fried last fall, I also replaced the front harness with one I bought from Jim just in case it was the harness after all. And with the new Haltech, and possibly the front harness, all the issues are gone now and AC is working great. I took it to my buddy's shop and had him charge it with R134a this time since he's a professional and I got tired of ruining compressors.