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A/C compressor not engaging [message #174208] Thu, 21 June 2012 14:12 Go to next message
carguy is currently offline  carguy   United States
Messages: 498
Registered: June 2006
Location: Coshocton OH
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Senior Member

My air conditioner compressor is not engaging. Following the procedure in the maintenance manual I shorted across the terminals on the pressure switch connector and the clutch engages. Per the manual this indicates that the pressure in the line is too low or the switch is defective.

Now my questions:
I'm using DuraCool I'm assuming that the pressure should be 20 -25 psi with the gauge connected to Gauge connection 1 ( see photo http://www.gmcmhphotos.com/photos/misc-gmc-photos/p44570-air-conditioning-clutch-not-functioning.html ). Is my assumption correct?

If the pressure is OK and I need to replace the pressure switch can I remove & replace the switch without opening the line and loosing the DuraCool?

Any comments/suggestions will be appreciated.

Bill Brown
Coshocton OH
'77 Buckeye Cruiser
Change is certain, progress is not


Bill Brown - '77 Buckeye Cruiser
Coshocton OH
carguybill@sbcglobal.net
Re: A/C compressor not engaging [message #174223 is a reply to message #174208] Thu, 21 June 2012 18:45 Go to previous message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
carguy wrote on Thu, 21 June 2012 15:12

My air conditioner compressor is not engaging. Following the procedure in the maintenance manual I shorted across the terminals on the pressure switch connector and the clutch engages. Per the manual this indicates that the pressure in the line is too low or the switch is defective.

Now my questions:
I'm using DuraCool I'm assuming that the pressure should be 20 -25 psi with the gauge connected to Gauge connection 1 ( see photo http://www.gmcmhphotos.com/photos/misc-gmc-photos/p44570-air-conditioning-clutch-not-functioning.html ). Is my assumption correct?

If the pressure is OK and I need to replace the pressure switch can I remove & replace the switch without opening the line and loosing the DuraCool?

Any comments/suggestions will be appreciated.

Bill Brown
Coshocton OH
'77 Buckeye Cruiser
Change is certain, progress is not


Bill,

The simple answer is - No.

Other issue, that is a high side pressure switch. It may have a set point that is higher than that.

I'm not near my books, so I can't be sure.

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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