My compressor cycles on and off. Is this an indication of low coolant? please advise

 

the compressor is supposed to cycle on and off, thats what they are designed to to, they have a electromagnetic clutch on them that turns them on and off. Is it blowing cold air? if not then you may have low refrigerant, but if its blowing cold air don't worry about it

 

The clutch should cycle every so often when the defrosters are on and all the time when A/C is on. All the other settings it shouldnt. cycle, I dont believe. If its blowing cool air, it should be fine.

 

Both are correct. Anytime the defrost is on it will cycle occasionally. With the AC on in any of the three positions, it will cycle regularly.... about once every 5 seconds or so for about 5 seconds and off for 5 and so on. Best way to know if you need refridgerant is to take a temp reading with one of those laser temp guns. It should cool air entering the cab I think it is 20 degrees cooler then the outside air. I think that is pretty standard for any ac system in a vehicle. And yes, you can overcharge your system. The only other way to make sure you have the proper amount is to have it evacuated with a professional evacuator pump machine and then have it refilled to the proper amount in pounds of refridgerant. Do not do this yourself, no matter how much you don't care about the environment. $10,000 to $25,000 per instance. Must be done and inspected by a certified tech. Not like any of us has done that without a license, though.