Magnum V8-5.7L VIN 2 (2007)
Air Door Actuator / Motor: Description and Operation
Mode Door Actuator
Description
DESCRIPTION
The mode door actuator (1) is a reversible, 12-volt direct current (DC), servo motor. The mode door actuator is located on the driver side end of the
HVAC air distribution housing, close to the instrument panel. The mode door actuator is mechanically connected to the floor, defrost/demist and the
panel-air doors.
The mode door actuator is interchangeable with the actuators for the blend-air door(s) and the recirculation-air door. 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
connect it to its door linkage and three integral mounting tabs (4) that allow the actuator to be secured to the HVAC housing. The mode door actuator
does not require mechanical indexing to the mode-air doors, as it is electronically calibrated by the A/C-heater control.
Operation
OPERATION
The mode 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 mode door actuator can move the floor, defrost/demist and the panel-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 mode-air doors will move in one direction. When the
A/C-heater control reverses the polarity of the voltage to the motor, the mode-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 mode-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 mode door actuator and the mode-air
doors. The A/C-heater control learns the mode-air doors stop position during the calibration procedure and will store a diagnostic trouble code (DTC)
for any problems it detects in the mode door actuator circuits.
The mode door actuator is diagnosed using a scan tool.
The mode door actuator cannot be adjusted or repaired and must be replaced if found inoperative or damaged.
