MOTOR-BLOWER
DESCRIPTION
The blower motor (1) is a 12-volt, direct current (DC)
motor mounted within a plastic housing with an inte-
gral wire lead and connector (2) and squirrel cage-
type blower wheel (3) that is secured to the blower
motor shaft (4). The blower motor wheel is located in
the HVAC air inlet housing which is mounted to the
passenger side end of the HVAC housing.
The blower motor can be accessed for service from
underneath the instrument panel.
OPERATION
The blower motor is used to control the velocity of air moving through the HVAC housing by spinning the blower
wheel within the HVAC air inlet housing at the selected speed or, in the ATC system, at the selected or programmed
speed.
On models equipped with the manual temperature control (MTC) heating-A/C system, the blower motor will operate
whenever the ignition switch is in the On position and the blower motor control in any position except Off. On mod-
els equipped with the automatic temperature control (ATC) system, the blower motor will operate whenever the igni-
tion switch is in the On position and the A/C-heater control power is turned on.
For the MTC system, blower motor speed is controlled by directing the ground path for the blower motor through the
correct resistor wire to obtain the selected speed.
For the ATC system, blower motor speed is controlled by the blower motor power module which provides the blower
motor with power and a path to ground. The blower motor power module also sends a blower control signal to the
A/C-heater control. Using input from the blower motor control (manual mode ) or sensor data (automatic mode), the
A/C-heater control processes the blower control signal from the power module and sets the speed at which the
blower motor will run.
The blower motor and blower motor wheel are factory balanced and cannot be adjusted or repaired. If faulty or
damaged, the blower motor and blower wheel must be replaced as an assembly.
DIAGNOSIS AND TESTING
BLOWER MOTOR
WARNING: On vehicles equipped with airbags, disable the airbag system before attempting any steering
wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the
negative battery (ground) cable, then wait two minutes for the airbag system capacitor to discharge before
performing further diagnosis or service. Failure to take the proper precautions could result in accidental
airbag deployment and possible personal injury or death.
NOTE: For circuit descriptions and diagrams, refer to Air Conditioning/Heater in Group 8W - Wiring Dia-
grams.
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DISTRIBUTION
WK