Theory Of Operation

After the initial installation of the HVAC Module, the controller is calibrated to each individual door actuator. The recirculation door actuator is connected to the HVAC Module or module by a dedicated two-wire lead and connector of the HVAC wire harness. When the HVAC Module pulls the voltage on one side of the control circuit high and the other low, the door actuator will move in one direction. When the HVAC Module reverses the polarity of the voltage to the motor the recirculation door actuator moves in the opposite direction. When the recirculation air door reaches its travel limit, the HVAC Module will turn the voltage off. Unlike the mode and blend door actuators, the recirculation door does not use a position sensor due to the door only has two positions of either open or closed. The HVAC Module learns the recirculation door stop positions during the calibration procedure.