General Information

The purpose of the heater is to supply heat to the interior of the vehicle. The vehicle operator can determine the level of heat by turning the air temperature switch, located on the HVAC control assembly, to any setting. The air temperature switch can change the vehicle's air temperature regardless of the HVAC mode setting, heater or A/C.

The IP fuse block provides power to the air temperature switch actuator through the ignition 3 voltage circuit. Power and ground is provided to the HVAC control assembly by the ignition 3 voltage and ground circuits.

When a desired temperature setting is selected, a variable resistor is used to determine the air temperature actuators value. The air temperature door position signal value is a varied voltage that is applied to the air temperature actuator motor.

The motor opens the air mixture door to a position to divert sufficient air past the heater core to achieve the desired vehicle temperature. Ground for the air temperature actuator is provided by the ground circuit.