I have an '01 1500 360. Last winter my a/c compressor kept kicking in and out while I had the heat on, certainly not using the a/c. It was annoying, so I pulled the relay, and it stopped doing it. I am now interest in fixing it. I'm not really sure what tells the compressor to kick in, and why it would do it when there is no signal coming from the switch on the console. I tested the relay, and it is good. Anyone have any ideas what may cause this?

 

I found on my climate control, the setting for vent/floor combo turns on the A/C even though its not marked with the snow flake. I believe others have noticed that also.
Also, you will get A/C on in both defrost modes.
So, only when you are in either Vent, or Floor only, the A/C is off.
For me at least. others?

 

You covered it 98 Dodge. That should be the case for all 2nd gens.

 

It helps with condensation on the inside of the windshield when defrosting supposedly. And also keeps the compressor from just sitting dormant for long periods so the seals and such get lubed and don't dry out.

 

The most likely culprit for the short cycling is a low refrigerant charge. You can buy a can of R-134a with a refrigerant gauge for under $20 at your FLAPS. It won't fix the reason it's leaking, but It'll refill the system for a while and stop the short cycling.

The clutch will stop working altogether if the charge gets too low to protect the compressor from burning up.