Pacifica V6-3.8L VIN L (2005)
Air Door Actuator / Motor: Description and Operation
Blend Door Actuator
Blend Door Actuator
The two blend door actuators for the dual zone heating-A/C system are reversible, 12-volt Direct Current (DC), servo motors.
For this dual zone heating-A/C system, one blend door actuator is mechanically connected to only the driver side blend-air door, while a second separate
blend door actuator is mechanically connected to only the passenger side blend-air door.
The blend door actuators are interchangeable with each other, as well as with the actuator for the mode-air doors and the recirculation-air door. Each
actuator is contained within an identical black molded plastic housing with an integral wire connector receptacle. Each actuator also has an identical
output shaft with splines that connects it to its respective door linkage and two integral mounting tabs that allow the actuator to be secured to the HVAC
housing. The blend door actuators do not require mechanical indexing to the blend-air doors, as they are electronically calibrated by the A/C-heater
control.
The A/C-heater control must be recalibrated each time an actuator motor is replaced.
Each blend door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector from
the HVAC wire harness. The blend door actuator can move the 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 blend-air door will move in one direction. When the A/C-heater control reverses the
polarity of the voltage to the motor, the 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 blend-air door stops and will not move. The motor connections also provide a feedback signal to the
A/C-heater control. This feedback signal allows the A/C-heater control to monitor the operation and relative positions of the blend door actuator and the
blend-air door. The A/C-heater control learns the blend door stop positions during the calibration procedure and will store a diagnostic trouble code
(DTC) for any problems it detects in the blend door actuator circuits.
The blend door actuator(s) can be diagnosed using a DRBIII(R) scan tool.
The blend door actuator(s) cannot be adjusted or repaired and, if damaged or faulty, they must be replaced.