2010 G37 blowing warm. Blower works, refrigerant at 34 psi compressor clutch will not kick on. Took it to the shop, told me it was a bad compressor but wanted $1,600 to repair. I ordered one online and put it in myself. First had the system Freon evacuated, hooked up my gauges and vac pump. Installed the compressor… still warm air and clutch not kicking on. Do you think it could be pressure switch or clutch/ compressor relay? I need help! Rico in Cincinnati

 

Probably pressure switch. Sounds like you were given bad advice/diagnosis.

 

See this post and run the IPDM/er self-test. This will test the magnetic clutch. If the clutch engages, then the issue moves to the pressure switch or the unified meter AC amp. If it does NOT engage, then you look to the IPDM/er. It might not hurt to check the fuse in that module anyway (#49, 10amp "AIR CONT").