a/c compressor only engages when engine is under load, for example, uphill and over 3000 rpm

Asked by msaddy May 13, 2014 at 04:51 PM about the 1993 Buick Park Avenue FWD

Question type: Maintenance & Repair

I have a 1993 Buick Park Avenue, 3.8, 4 speed automatic. The a/c compressor will
come on, but usually only when there is a load on the engine, for example, going uphill,
rpms go over 3000, and I get cold air. On the downhill side, or at idle, the a/c clutch
does not seem to engage. Mechanic says I am a little low on Freon, but that even
when jumpering the power and the ground, clutch does not engage.Thanks for your
help. I don't want to put $700 for a new compressor into a $700 car!

1,195

Jim answered 10 years ago

If you are low on refrigerant then the low pressure switch will not close and the clutch will not engage. It is the sensor on the side of the receiver/dryer. Remove the connector and jump it with a paper clip. Then see if the clutch engages. If it does either you are low on refrigerant or the switch is bad. You can change the switch without losing Freon.

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msaddy answered 10 years ago

Thank you, Jim, We tried the jumper, and clutch did not engage. Can you suggest another step? Thanks!

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