GM Repair Problems? Ask GM Repair Expert Now.
Hello and thank you for your question,What year and make is you GMC and when you checked your pressure after it stopped cooling was the compressor running?
Can you tell me the year and make of you GMC so I can have a look at the correct diagrams?
Okay if the relay is actually at fault before you replace it or anything else can you take a 12 volt test light and or a volt meter and check and see if you are getting battery voltage at the compressor clutch with the AC on when the clutch will not engage. The power feed from the relay is the green wire, check this for me and post back with the results.
Let me know, Im here when you ready.