Circuit Description
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The mode actuator is an electronic device that incorporates a stepper motor and a feedback potentiometer. The HVAC control module controls the mode door position by sending a control signal to the actuator. The signal's value is dependent upon the desired mode that the vehicle occupants select. While the actuator moves, the potentiometer produces the Actual Door Position signal that is sent to the HVAC control module. The HVAC control module continues to command the actuator to move until the desired value is equal value. The door directs airflow through the outlets which were selected by the vehicle occupants.