Aspen 2WD V8-5.7L (2007)
Air Door Actuator / Motor: Description and Operation
Controls - Front
Description
DESCRIPTION
Models with the single zone heating-A/C system have a single blend-air door, which is controlled by a single blend door actuator (1). Models with the
dual zone system have two blend-air doors, which are controlled by two blend door actuators. The blend door actuators are reversible, 12-volt direct
current (DC), servo motors.
The blend door actuator for the single zone heating-A/C system is located on top of the HVAC housing, behind the dash panel.
For the dual zone heating-A/C system, the same blend door actuator used for the single zone system becomes the driver side blend door actuator, which
is mechanically connected to only the driver side blend-air door. A second separate blend door actuator located on the bottom of the HVAC housing is
mechanically connected to the passenger side blend-air door.
The blend door actuators are interchangeable with the actuators for both 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. Three integral mounting tabs allow the actuator to be secured to the
HVAC housing. Each actuator also has an identical output shaft with splines that connects it to a blend-air door. 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.
Operation
OPERATION
The blend door actuators are 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(s) can move the blend-air door(s) 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
A/C-heater control uses a pulse-count positioning system to monitor the operation and relative position of the blend door actuator(s) and the blend-air
door(s). The A/C-heater control learns the blend-air 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 actuators are diagnosed using a scan tool.
The blend door actuators cannot be adjusted or repaired and must be replaced if found inoperative or damaged.
Description
DESCRIPTION