Grand Cherokee 2WD L6-242 4.0L VIN S MFI (1993)
Blower Motor: Service and Repair
Information
BLOWER MOTOR
The blower motor and blower wheel are located in the passenger side end of the heater-A/C housing, below the glove box module. The blower motor
controls the velocity of the air flowing through the heater-A/C housing by spinning a squirrel cage-type blower wheel within the blower housing at the
selected speed. The blower motor and blower wheel can be serviced from the passenger compartment side of the housing. The blower motor circuit is
protected by a fuse in the junction block.
The blower motor will only operate when the ignition switch is in the On position, and the heater-A/C mode control switch is in any position except Off.
On models with the standard manual temperature control system, the blower motor speed is controlled by the blower motor switch and resistor. On
models with the optional Automatic Temperature Control (ATC) system, the blower motor speed is controlled by the blower motor switch and the power
module.
The blower motor and blower wheel cannot be repaired and, if faulty or damaged, they must be replaced. The blower motor and blower wheel are each
serviced separately.
BLOWER MOTOR RESISTOR
Models with the standard manual temperature control system have a blower motor resistor. The blower motor resistor is mounted to the heater-A/C
housing, under the instrument panel and just inboard of the blower motor. It can be accessed without removing any other components.
The resistor has multiple resistor wires, each of which will change the resistance in the blower motor ground path to change the blower motor speed. The
blower motor switch directs the ground path through the correct resistor wire to obtain the selected blower motor speed.
With the blower motor switch in the lowest speed position, the ground path for the motor is applied through all of the resistor wires. Each higher speed
selected with the blower motor switch applies the blower motor ground path through fewer of the resistor wires, increasing the blower motor speed.
When the blower motor switch is in the highest speed position, the blower motor resistor is bypassed and the blower motor receives a direct path to
ground.
The blower motor resistor cannot be repaired and, if faulty or damaged, it must be replaced.