Blower Motor - Operation

OPERATION

The blower motor controls the velocity of air moving through the HVAC housing by spinning the blower wheel at the selected or programmed speed.

On the Manual Temperature Control (MTC) heating and A/C system, blower motor speed is controlled by regulating the path to ground through the blower control switch and the blower motor resistor. With the Automatic Temperature Control (ATC) heating and A/C system, blower motor speed is controlled by an electronic blower motor power module, which uses a pulse width modulated input from the A/C heater module and a feedback signal from the blower motor to regulate the blower motor ground path. On both systems, the blower motor will operate whenever the ignition is in the Run position, and the blower motor control in any position except Off. The blower motor receives battery current from the Power Distribution Center (PDC).

On ATC equipped models, the blower motor control system is diagnosed using a scan tool .

The blower motor and blower motor wheel are factory balanced as an assembly and cannot be adjusted or repaired and must be replaced if inoperative or damaged.