Rear Actuator Blend Door

Rear Actuator Blend Door

Description






The rear blend door actuator (1) is a reversible, 12 volt direct current, servo motor. The rear blend door actuator is located on the back side of the rear HVAC housing.

The rear blend door actuator is contained within a black molded plastic housing with an integral wire connector receptacle (2), an output shaft with splines (3) that connect it to the rear blend-air door and three integral mounting tabs (4) that allow the actuator to be secured to the rear HVAC housing. The blend door actuator does not require mechanical indexing to the blend door linkage, as it is electronically calibrated by the HVAC control.

The HVAC control must be calibrated each time an actuator motor is replaced.

The rear blend door actuator is interchangeable with the actuator for the rear mode-air door.

Operation

The rear blend door actuator is connected to the HVAC control through the vehicle electrical system by a dedicated two-wire lead and connector of the rear HVAC wire harness. The rear blend door actuator can move the rear blend-air door in two directions. When the HVAC control pulls the voltage on one side of the motor connection high and the other connection low, the rear blend-air door will move in one direction. When the HVAC control reverses the polarity of the voltage to the motor, the rear blend-air door moves in the opposite direction. When the front HVAC control makes the voltage to both connections high or both connections low, the rear blend-air door stops and will not move.

The front HVAC control uses a pulse-count positioning system to monitor the operation and relative position of the rear blend door actuator and the rear blend-air door. The front HVAC control learns the rear blend-air door stop positions during the calibration procedure and will store a diagnostic trouble code for any problems it detects in the rear blend door actuator circuits.

The rear blend door actuator is diagnosed using a scan tool.

The rear blend door actuator cannot be adjusted or repaired and must be replaced if inoperative or damaged.