Air Temperature Actuator

The air temperature actuator opens the air mixture door to a position to divert sufficient air past the heater core to achieve the desired vehicle temperature. The air temperature actuator is a 5 wire actuator that incorporates a electric motor with feed back capability. Power is provided by ignition 3 voltage circuit through the left I/P fuse block. Ground is provided by the ground circuit through the HVAC control module. The air temperature actuator has a potentiometer integral to it. A 5-volt reference signal is sent out over the 5-volt reference circuit to the air temperature actuator. A feed back signal is provided by the air temperature door position signal circuit. As the actuator moves the voltage on the door position signal circuit changes. The HVAC control module monitors this signal to calculate the actual door position.

The control of the air temperature actuator is provided by the air temperature door control circuit. When a request of actuator position change from the HVAC control module, the air temperature door control circuit voltage is varied. A 2.5 volt signal from the HVAC control module keeps the actuator stationary. A 0 volt or 5 volt signal from the HVAC control module allows the actuator to rotate to a position determined by the HVAC control module.