on my 89 iroc my compressor wont run. i had to get a 90-92 compressor clutch connector from the junkyard because i only had the old style with the diod in it and splice that into the harnes. but my compressor still wont run. i havent checked pressure in my ac system but i vented a little and there was still some in there(im going on the assumption that it has enough to run). i took a multimeter to the plug and found 0 power at the connector for the compressor clutch when i signal for ac at the evirtonmental controls and the fan didnt kick on.. so im leaning towards the evvironmental controls not functioning properly. my question is how can i test if the i have power to the controls when i signal for ac.

 

Just for argument's sake, jumper the low pressure cutout switch to see if the compressor will run. Don't assume system pressure is adequate unless you have connected a gauge set.