A/C Compressor is kicking off and on

[RC1981]

I have a 1994 K1500, 5.7 and have replaced a ton of new parts since I bought it 8 months ago. The most recent part replaced was the a/c compressor. After putting the new compressor on it kicks off and on non stop when my heater is running. What would make the compressor turn off and on while the heat is running? What can I do to fix this problem? Any help is greatly appreciated!

Note: I bought the compressor new, not a re-man unit. Also replaced the evaporator tube and accumulator at the same time.


Thanks,
Rusty

 

[67chevymechanic]

Sounds like the system may be low on refrigerant. To check it without gauges, feel the line (the big one) on the backside of the compressor. It should be cold and sweating. If not, read on. Put the A/C on max, fan on high, windows down. Does it still kick on and off rapidly? If so, assuming you don't have a set of A/C gauges, go to the parts store and pick up a can of R-134a and a charging hose. Follow the directions on the can and charge the system until you have a cold sweat all the way up to the back of the compressor on the low side line (the big one). *Careful not to touch the little line. It's hot.* Then your system is fully charged. It is normal for the compressor to come on with the heat though. It will cycle on and off, but it should be a long period of time between clutch cycling.

 

[Joesgarage]

The compressor will cycle when the defrost is on.
shouldn't be cycling if its just on floor heat. Might be the heater control in the dash.
Steve

 

[67chevymechanic]

mine cycles on and off on floor or defrost. But mine's an '89, so the controls are a bit different than a '94. The '94 has a recirc button and a 4 speed fan instead of a 3 speed. Who knows the way GM has them wired up...