Commander 4WD V8-4.7L VIN N (2006)
Air Door Actuator / Motor: Description and Operation
Rear Blend Door Actuator
ACTUATOR-BLEND DOOR
DESCRIPTION
The rear blend door actuator (1) is a reversible, 12 volt direct current (DC), servo motor. The rear blend door actuator is located on the back of the rear
HVAC housing. The rear blend door actuator is interchangeable with the actuator for the mode-air door. Each actuator is contained within an identical
molded plastic housing with an integral wire connector receptacle (2). Three integral mounting tabs (4) allow the actuator to be secured to the rear
HVAC housing. Each actuator also has an identical output shaft with splines (3) that connects it to the rear air door. The rear blend door actuator does
require mechanical indexing to the rear blend-air door, as it is electronically calibrated by the A/C-heater control.
OPERATION
The rear blend door actuator is connected to the A/C-heater 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 A/C-heater 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 A/C-heater
control reverses the polarity of the voltage to the motor, the rear blend-air door moves in the opposite direction.
When the A/C-heater control makes the voltage to both connections high or both connections low, the rear blend-air door stops and will not move. The
A/C-heater 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 A/C-heater control learns the rear blend-air door stop positions during the calibration procedure and will store a diagnostic trouble
code (DTC) for any problems it detects in the rear blend door actuator circuit.
The rear blend door actuator cannot be adjusted or repaired and, if faulty or damaged, it must be replaced. The rear blend door actuator is diagnosed
using a scan tool.
