Defrost/Panel/Floor Mode Door Position
Airflow through the HVAC plenum is controlled by the defrost/panel/floor mode door actuator. The defrost/panel/floor mode door actuator contains a reversible electric motor and potentiometer. The potentiometer allows the HVAC control module to monitor the position of the defrost/panel/floor mode door. The potentiometer circuit consists of a 5-volt reference signal connected to one end of a variable resistor, and a signal ground connected to the other. A signal circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal to the HVAC control module from the contact wiper indicates the position of the defrost/panel/floor mode door. The HVAC control module powers the actuator motor to move the defrost/panel/floor mode door to the desired position. The desired position is set by the vehicle occupants using the mode selector buttons.