I am in the process of rebuilding my A-6 compressor.Is there a way to test the superheat switch on the bench? Isn"t it just a normally closed switch that opens when compressor temps get to high? Any expert advice would be appreciated. Thanks, Don :cool:

Originally posted by dc_malibu:
Is there a way to test the superheat switch on the bench? Isn"t it just a normally closed switch that opens when compressor temps get to high? Don, are you sure its a "superheat" switch. Superheat is the condition of the refrigerant returning to the compressor. It is measured utilizing gauge pressure converted to temperature and the actual temp of the return line reflecting the temp of the refrigerant.
Is it the compressor overload safety that you are refering to?
Rob

While I agree with Rob about the true definition of "superheat" GM named it "Superheat Switch" . It closes on either high compressor discharge temp or low discharge pressure. In an operating system if this switch closes a heating element melts a fuse link in the "Thermal limiter" removing power from the clutch coil. The thermal limiter is one time only operation and must be replaced if the fuse link melts.

Trivia: This switch was first used on 72's. In 78 the switch was replaced by a pressure switch only.

As far as testing it, it should be closed with no pressure on it, don't know how you would test the temp function. You can heat it but with the pressure switch closed you wouldn't be able to measure/detect the temp switch operation.

Maybe someone else has additional information.

Note: Don't connect the thermal limiter to the superheat switch until after charging the system.