I am having an a/c problem. I have a 2001 Chev. 2500 HD, extended cab truck with a 6.0 v8 and auto trans. The problem is that the a/c seems to cycle.
It will start blowing cool air and run fine for awhile, then the cool air will stop. shortly the cool air will start again. The fan works fine, just the cool air stops.
It may stop for just a couple of minutes or it could last for 15 or 20 minutes. The system will start working again and begin to cool for a period of time, the stop cooling. I have noticed that this most apparent when the outside temp is very warm.
I have checked the pressures and they appear to be in order and do not appear to show low freon in the system. Not sure what the problem could be, wondering if it could be the low pressure cutoff switch or something else along these lines.
Thank you very much for your time. I appreciate it very much
Hey there Ron,
The next time it stops blowing cold air get out and look at the a/c compressor clutch to see if the compressor is still running or has shut off. If the compressor is off for an extended period of time, you could have a problem with one of the following:
1. Control problem coming from the dash control head,
2. Low or high pressure switch problem shutting the compressor off
3. A compressor clutch or compressor problem
4. A restriction in the system somewhere and the pressures are too high, and the system is shutting down.
When this happens, check for power to the compressor clutch and work your way backwards into the cab of the vehicle looking for the loss of power culprit.
If the compressor is still running (meaning the compressor clutch is spinning around) you could have a problem with the following:
1. Low on Freon
2. A control head problem in the dash of the vehicle
3. An air flow problem in the dash of the vehicle blending hot coolant from the heater core with the cold air from the compressor
4. A problem with the compressor internally
Feel the heater hoses going into the cab of the vehicle under the hood. If both are very hot, take a pair of vise grip pliers and block off the inlet hose to stop the flow of hot coolant to the heater core inside the dash. If this helps make the air colder, you probably have a heater control problem.
If the compressor “short cycles” meaning it quickly and frequently turns on and off then you could have a pressure switch problem, low Freon issue or a restriction in the system.
Austin C. Davis