2009 grand Cherokee a/c issue

[sb68]

Have a 2009 grand Cherokee 102,000miThat there a/c compressor started screeching real bad. Can see the clutch slipping when noise occurs. I tried 2 different uses compressors one I bought online and one from a salvage yard. Both had the exact same problem. So at that point I replaced the compressor with a new one along with a new expansion valve, accumulator/dryer and pressure switch. Before replacing the new parts the system was evacuated and the correct amount of compressor oil added. Recharged the system and it seemed to work perfectly fine for about a week and has started doing the same thing again with the compressor noise with the clutch slipping. One other thing I’ve noticed that I’m not sure is related to the clutch slipping/noise issue or not is that the compressor cycles on and off with the control set to the panel position even when the a/c itself is not even turned on.

trying to see if anyone else has had this issue and/or my know the cause of it. Thanks in advance

[sb68]

I think I’ve figured out a couple things. First I think the radiator fan should be turning on and running all of the time when the a/c is turned on but it’s not. It’s cycling on and off. I’ve noticed with gauges hooked up that as soon as the fan turns of the high side pressure shoots up to around 300 and the compressor clutch will start screeching then fan will turn on and pressure will come back down and compressor quiets down. Other thing I’ve noticed is when the a/c is on the engine idle is only around 500rpm. I think when the a/c is turned on it should bump the idle speed up but it’s not. With the a/c off the radiator fan is cycling as it should when the engine gets up to temp. Does anyone know what tells the radiator fan to turn on with a/c and also the engine rom to bump up? I think the issues may be related but I’m not sure.