The clutch on my a/c compressor keeps engaging and disengaging
even with the a/c switch off, and with the a/c on the air
isnt cold. Any ideas ? Could it be the a/c relay ?

 

No, it's the low pressure switch on the low side. When your compressor kicks in it lowers the pressure on the low side and the switch opens then when the pressure equalizes the switch turns the compressor back on.

The cause is you need to add some refrigerant to the system. It's low.

Edwin

 

Have the system checked by an a/c shop.

Yes it could be low (this means you have a leak that needs to be fixed) It could also be a faulty low pressure switch, faulty thermostatic sensor, on/off switch etc. etc etc.

 

A/C is on when defrost is on. air conditioned air is dryer and therefore a/c is used to help defrost windows.

 

Mine did the same thing. I took the truck to the dealer on Monday. It was 2 units low on Refrigerant. They couldn't identify a leak yet but there must be a good one.

Bob