Cycling A/C Compressor
Any air conditioner experts out there? My dash air was operating just fine until a couple of days ago. Here's the deal. I start the rig and turn on the dash air. I can hear the compressor pull the eng...
Forum Discussion
marcsbigfoot20b27 wrote:dougrainer wrote:
If it gets to the hi 50's then the charge is not a factor. Low charge would cause short cycling at the beginning. I would suspect a BAD tstat. Jump the 2 wires on the Tstat (the tstat is at the Evaporator) and see if it stops cycling. Doug
There is no tstat per se, on a fixed orifice cycling clutch system. The pressure of the low side (which is directly related to temperature of the evap) is the "thermostat" if you will.
Reasons for low pressure shut off are:
Protect compressor due to really low charge......no freon , no oil.
Protect compressor from getting liquid in low side port.....no evap fan or iced evap.
Prevent evap from getting to cold in higher humidity and freezing evap and blocking airflow.
I have been working ON and fixing RV CLASS A Motorhome Dash AC systems for 35 years. NO RV CLASS A DASH AC system uses a Orifice type system. They ALL use a 12 volt point type Tstat that has the sensor INSTALLED the Evap fins. THAT tstat is what controls the power to the compressor as long as the pressure switches and coolant charge is correct. Doug
