A crankcase heater is a small eclectic heater that keeps the compressor oil at a relatively warm temp. This allows the oil to circulate in the system at lower temperatures.
The formula used to determine the power consumed by a compressor's crankcase heater is the overall volume times the amount of heat generated. This allows a person to purchase the appropriate heater for their application.
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If you are talking about a wall switch for the heater, check to see if the heater has its own internal thermostat or switch as this might be in the off position and not allow the heater to turn on. If you are talking about a switch on the heater itself, then yes in all probability the switch is not working.
Where is heater control switch
to prevent liquid refrigerant from staying in the compressor after shut down
Where is the heater relay switch on a 2005 MalibuRead more: Where_is_the_heater_relay_switc
There is not a pressure switch however there is a temp warning sensor on the back of the crankcase in the bottom
IT turns the heater on and off!
It could be the high speed heater motor relay is stuck on or the switch itself is broken.
A restricted/plugged heater core can do that. Try flushing the heater core.
Your heater switch may not need to be replaced. The heater high position is controlled by a fuse under the hood. Until you find the fuse and replace it, your new switch will not work. JRR.