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Air Coditioner Question

884 views 5 replies 6 participants last post by  302 Z28 
#1 ·
Hey guys I just bought a 88 chevy 1500. It has A/C and it works fine. The question is the compressor, it constantly cuts on and off. I'm curious as to what is causing the compressor to cut on and off. Could there be something wrong. Possibly a bad switch.
 
#3 ·
You are probably low on freon .
There is a low pressure cut-out sensor that is causing the compressor to cycle .
While the compressor is running the low side (suction) pressure decreases . If you are low on refrigerant the pressure drops too low & then cuts out the compressor until the pressure from the high side equalizes , which then increases the low side then it starts to cycle again .
Another reason could be if you have your control set on "defrost" this could also engage the compressor .
If this is the case there probably is not anything wrong with the compressor it is cycling because of the low temperature outside .
Hope this was helpful . 55mole
 
#5 ·
Throw some guages on it, if the high side is too high and the low side too low, you could have a partially plugged orifice tube.

If both sides are low, you're probably low on refrigerant.

From the description, I would say the latter is true.
 
#6 ·
The weather took a warm turn this week, and when I flipped on my AC in my truck, it didn't cool very well. Stuck the gages on it and discovered it was low on R134. Went to the local Auto Zone and bought three cans. Shorted out the low pressure switch and started dumping the stuff in. It was cooling like a son of a gun. Reconnected the low pressure switch and the compressor started cycling on and off. The pressures were right on, so it had to be the switch. Went down to the local Car Care AC Delco dealer and plopped down $19 for a new one. The switch is on a stub in with a shrader valve, so it can be changed without loosing too much freon. Good for another couple of years.

Vince
 
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