2002 Sierra 1500HD a/c issues

[Chris Boaz]

Good afternoon folks. I'm a new guy to this forum. I have a 2002 GMS 1500HD. It has the 6.0 V8.

 

My a/c has some issues. It started off not cooling well at idle. So at the advice of a mechanic friend we replaced the fan clutch, no change. so then we got to diagnosing further. I appeared to have a bad high pressure switch. So I changed the high and low side switches. We evacuated the system and then recharged the system. A/C was blowing cold, until I took it for a spin. About 5 miles into the trip the a/c compressor quit and will not recycle. I have checked the relay and Freon pressure. Everything seems to be where it is supposed to be. Anyone ever have this kind of troubles? I have also checked the a/c clutch switch on the accumulator, same story. I'm at my wits end. Can anyone shed some light on this subject? The compressor will kick in if you remove the relay and bypass the terminals. I'm at a loss. Thank you in advance for your help.