Blower Motor: Description and Operation

Fig.7 Blower Motor:

FRONT BLOWER MOTOR
The blower motor is a 12-volt, Direct Current (DC) motor with a squirrel cage-type blower wheel that is secured to the blower motor shaft. The blower motor and wheel are located near the passenger side end of the heater-A/C unit within the two halves of the intake air housing in the passenger compartment below the instrument panel. The blower motor and blower motor wheel are a factory balanced unit and cannot be adjusted or repaired. If faulty or damaged, the blower motor and blower wheel must be replaced as a unit.

The blower motor will operate whenever the ignition switch is in the ON position and the heater-A/C control power is turned on. The blower motor can only be turned OFF by turning OFF the power at the heater-A/C control. The blower motor receives battery current whenever the front blower motor relay is energized. The front blower motor relay output circuit is protected by a fuse in the Intelligent Power Module (IPM) located in the engine compartment near the battery. In the Manual system, the blower motor speed is controlled by regulating the path to ground through the blower control switch and the blower motor resistor. In the ATC system, the blower motor speed is controlled by an electronic blower power module, which uses a pulse width modulated input from the ATC module and feedback from the blower motor to regulate the blower motor ground path it provides. The blower motor and wheel are used to control the velocity of air moving through the heater-A/C unit housing. The blower motor controls the velocity of the air flowing through the heater-A/C housing by spinning the blower wheel within the housing at the selected speed or, in the ATC system, at the selected or programmed speed.

Fig.3 Blower Motor:

REAR BLOWER MOTOR
The blower motor is a 12-volt, Direct Current (DC) motor with a squirrel cage-type blower wheel that is secured to the blower motor shaft. The blower motor and wheel are located in a housing near the top of the rear heater-A/C unit in the passenger compartment behind the right rear wheel house. The rear heater-A/C unit housing must be removed from the vehicle to access the blower motor and blower wheel for service. The blower motor and blower motor wheel are a factory balanced unit and cannot be adjusted or repaired. If faulty or damaged, the blower motor and blower wheel must be replaced as a unit.

The rear blower motor will operate whenever the ignition switch is in the ON position, the heater-A/C control power is turned ON, and the rear heater-A/C system control switch on the front heater-A/C control is not in the OFF position. The blower motor can only be turned OFF by turning OFF the rear system at the front heater-A/C control. The blower motor receives battery current whenever the rear blower motor relay is energized. The rear blower motor relay output circuit is protected by a fuse in the Intelligent Power Module (IPM) located in the engine compartment near the battery. In the MTC system, the blower motor speed is controlled by regulating the path to ground through the blower control switch and the blower motor resistor. In the ATC system, the blower motor speed is controlled by an electronic blower power module, which uses a pulse width modulated input from the ATC module and feedback from the blower motor to regulate the blower motor ground path it provides. The blower motor and wheel are used to control the velocity of air moving through the rear heater-A/C unit housing. The blower motor controls the velocity of the air flowing through the rear heater-A/C housing by spinning the blower wheel within the housing at the selected speed or, in the ATC system, at the selected or programmed speed.