2010 Yukon denali
8 Answers
If the a/c compressor runs (cycles) on/off, check the refrigerant charge, it may be low.
I did that and it's not low. And after I unhooked battery for a while it worked got cold but then went back to cycling.
When the compressor is running and the ambient temperature is around 80 degrees, you should have 45-55PSI on the low side and 225-250PS on the high side. If the pressure is good then you have to check the switch on the low pressure line, it can be malfunctioning. Also, a bad expansion valve can create the on/off cycling.
When it turns onlow side only goes down ton 80 then it turns off. But also the ac Red light on the switch turns on and off when it cycles.
Well, understand that it's not easy diagnosing a problem such as this without being able to test the vehicle. The compressor clutch sensor switch may have gone bad or, judging by what you say about the control switch, it may have a problem and is working intermittently.
Short cycling would probably be low refrigerant level or a bad pressure switch. Cycling on and off occasionally would be normal unless you have the AC maxed out.
