Dakota 2WD V8-4.7L VIN J (2005)
Air Door Actuator / Motor: Description and Operation
Actuator-Blend Door
The blend door actuator (1) is a reversible, 12 volt direct current (DC), servo motor. The blend door actuator is located on the top of the HVAC housing.
The blend door actuator is interchangeable with the actuators for the mode-air and recirculation-air doors. Each actuator is contained within an identical
black molded plastic housing with an integral wire connector receptacle (2). Each actuator also has an identical output shaft with splines (3) that connects
it to its respective door linkage and three integral mounting tabs (4) that allow the actuator to be secured to the HVAC housing. The blend door actuator
does not require mechanical indexing to the blend-air doors, as it is electronically calibrated by the A/C-heater control.
The blend door actuator can be accessed for serviced by removing the instrument panel.
The 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
HVAC wire harness. The blend door actuator can move the blend-air doors 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 blend-air doors will move in one direction. When the A/C-heater control reverses the
polarity of the voltage to the motor, the blend-air doors moves in the opposite direction.
When the A/C-heater control makes the voltage to both connections high or both connections low, the blend-air doors stop and will not move. The
A/C-heater control uses a pulse-count positioning system to monitor the operation and relative position of the blend door actuator and the blend-air
doors. The A/C-heater control learns the blend-air doors stop positions during the calibration procedure and will store a diagnostic trouble code (DTC)
for any problems it detects in the blend door actuator circuit.
The blend door actuator is diagnosed using the scan tool.
The blend door actuator cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
