Front Auxiliary HVAC Control Assembly

The front auxiliary HVAC control assembly provides inputs to the auxiliary HVAC control processor. It is located in the overhead console so that front seat occupants can control auxiliary HVAC operation. This assembly provides blower, air delivery mode, air temperature settings and control of which control unit will operate the auxiliary HVAC system. When the REAR position is selected, inputs from this control assembly will not be processed by the auxiliary HVAC control processor. This system does not have Class 2 communication available.

The front auxiliary HVAC control assembly receives power from the ignition 3 voltage circuit. Ground is provided by the ground circuit to a splice pack. The front HVAC control assembly will apply a ground to the rear auxiliary enable control circuit when REAR is selected. When the air temperature knob is rotated a variable resistor internal to the assembly will vary a 12 volt input. The 12 volt varied voltage is supplied to the auxiliary HVAC control processor for an auxiliary air temperature actuator position change request.

This is done on the auxiliary air temperature door position signal circuit. When the voltage signal is low a cool air request is made and the voltage signal is high a warm air request is made.