Blower motor resistor

FRONT

DESCRIPTION

During vehicle assembly, the blower motor resistor is mounted to the dash plenum panel inside the passenger compartment prior to instrument panel roll-up (Fig. 2). 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. See Blower Motor Resistor in the Removal and Installation section of this group for more information.

OPERATION

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.

Fig. 2 Blower Motor Resistor - Factory Installation

1 - PLENUM PANEL

2 - SCREW

3 - RESISTOR

4 - CONNECTOR

5 - SCREW

6 - RESISTOR MOUNTING PLATE

REAR

DESCRIPTION

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.

OPERATION

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.