Operation CHARM: Car repair manuals for everyone.

Auxiliary Heating Operation

When an auxiliary warm air request is made the front auxiliary HVAC control assembly will send a high voltage signal to the auxiliary air temperature actuator on the auxiliary air temperature door position signal circuit. This voltage signal is a varied 12 volt signal. This signal is monitored by the logic incorporated in the actuator and it will move the actuator in the desired direction when a position change is requested.