Overtemperature Compressor Cut-off


Well-known member
This is a little known fact that I posted about 4-5 years ago when I was living in the HOT California Central Valley (Porterville area) with daily summertime afternoon temperatures over 110 degrees. The compressors (main electricity to cooling component) in our RV air conditioners ( at least the Dometic brand models for sure) HAVE A THERMAL OVERHEATING CUT-OFF SWITCH MOUNTED TO THE TOP OF THE COMPRESSOR. This switch can turn off the compressor and the cooling leaving the noisy fan blowers ON in VERY HIGH ambient temperatures WITHOUT YOU REALIZING WHAT IS HAPPENING. You will only notice a loss of cooling and the loss of the low volume, low frequency, rumble noise of the compressor. This is usually partially caused by a failing rooftop portion of the air conditioner. You can buy just the new rooftop 1/2 of most of the AC units on E-Bay.
You can buy infrared thermometers for modest prices on Harbor Freight Tools or E-Bay, which make checking Air Conditioner performance (along with tire temperatures, oven temperatures, truck cooling system, hot circuit breakers, etc.) pretty easy. The theoretical ooling for freon RV (and automotive) air conditioners is 20 degrees of cooling between the air inlet to the AC unit to the nearest cool air outlet to the AC unit.