Durango 2WD V8-5.2L VIN Y (1999)
Blower Motor Resistor: Description and Operation
SYSTEM DESCRIPTION
Front
Blower Motor Resistor - Factory Installation
During vehicle assembly, the blower motor resistor is mounted to the dash plenum panel inside the passenger compartment prior to instrument
panel roll-up. However a resistor mounting plate has been designed so that the resistor can be removed through an access hole in the cowl plenum
panel just below the windshield. It can be accessed by removing the cowl plenum cover/grille panel.
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 through the high speed blower motor relay
The blower motor resistor cannot be repaired and, if faulty or damaged, it must be replaced.
Rear
The blower motor resistor for the optional rear overhead A/C unit is located within the unit housing. 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.
