AC help....clutch disengages....not cold - The 1947 - Present Chevrolet & GMC Truck Message Board Network

iluvmy72 · 08-06-2006, 03:25 PM

OK.....if my AC system is low on freon, would this cause the clutch to engage and then disengage periodically? My AC system is not as cold as it once was....but could this be a bad clutch as well? How do I test?

byrd · 08-06-2006, 06:49 PM

If it engages in very short periods the system is low on freon and the low pressureis causing it to cycle. not sure how to test the clutch itself, but I really think it is just low on freon.

Old Yeller 1970 · 08-06-2006, 06:59 PM

Sounds low on freon. I had the same situation earlier this summer. I suggest buying a can or two of freon that says something like "Stop Leak" or "Leak Prohibitor" and a charge line. That should get you going, assuming you are running R134a. If you still have R12 you may have to get a mechanic to switch it over to R134a because you won't be able to buy R12.

Tynee · 08-06-2006, 07:29 PM

Somebody will be along to correct me if I'm wrong, but there may be a low pressure switch in the system that senses when the refridgerant level is low, and disengages the compressor. To get an idea of whether or not you you have other issues besides low refridgerant, like a problem with the clutch, you could jumper that wiring connector going into that switch and make it keep the compressor engaged long enough to be able to decide whether you have other issues.

robsm88 · 08-06-2006, 10:12 PM

Jump the wires on the plug for the low side pressure switch. That will engage the clutch if the compressor is being fed power. Don't do it for long though, because the clutch is being turned off to prevent compressor damage. 9 times out of 10, clutch is cycling due to low pressure. Put some gauges on there to check pressures. I personally would avoid the stop leak if possibe and just repair the leak.

08-06-2006, 03:25 PM	#1
iluvmy72 Registered User Join Date: Jan 2002 Location: Springville, UT, USA Posts: 1,010	AC help....clutch disengages....not cold OK.....if my AC system is low on freon, would this cause the clutch to engage and then disengage periodically? My AC system is not as cold as it once was....but could this be a bad clutch as well? How do I test?

08-06-2006, 06:59 PM	#3
Old Yeller 1970 DON'T TREAD ON ME Join Date: May 2005 Location: Crosby County, TX Posts: 989	Re: AC help....clutch disengages....not cold Sounds low on freon. I had the same situation earlier this summer. I suggest buying a can or two of freon that says something like "Stop Leak" or "Leak Prohibitor" and a charge line. That should get you going, assuming you are running R134a. If you still have R12 you may have to get a mechanic to switch it over to R134a because you won't be able to buy R12. __________________ Old Yeller

08-06-2006, 07:29 PM	#4
Tynee I miss this truck. Join Date: Dec 2001 Location: Lexington, KY U.S.A. Posts: 2,863	Re: AC help....clutch disengages....not cold Somebody will be along to correct me if I'm wrong, but there may be a low pressure switch in the system that senses when the refridgerant level is low, and disengages the compressor. To get an idea of whether or not you you have other issues besides low refridgerant, like a problem with the clutch, you could jumper that wiring connector going into that switch and make it keep the compressor engaged long enough to be able to decide whether you have other issues. __________________ '07 GMC Acadia SLT. Sweet ride. '08 Crew Cab Z-71 short bed. Really like this truck A LOT.

08-06-2006, 10:12 PM	#5
robsm88 Registered User Join Date: Apr 2006 Location: az Posts: 114	Re: AC help....clutch disengages....not cold Jump the wires on the plug for the low side pressure switch. That will engage the clutch if the compressor is being fed power. Don't do it for long though, because the clutch is being turned off to prevent compressor damage. 9 times out of 10, clutch is cycling due to low pressure. Put some gauges on there to check pressures. I personally would avoid the stop leak if possibe and just repair the leak.



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