I have a 2004 Grand Prix and the AC clutch is not energizing. I have checked the AC pressure on the low side and it was at around 150. High. I checked all fuses and relays and replaced them. Still nothing. I cannot find a pressure sensor on the low side. I did find one on the high side and unplugged it. Unplugging it should tell me that I do not have high pressure because the compressor didn't kick in. Any suggestions?