Blower Motor Resistor Block: Operation
WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
The resistor has multiple resistor circuits 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 circuit 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 circuits. Each higher speed selected with the blower motor switch applies the blower motor ground path through fewer of the resistor circuits, increasing the blower motor speed.
The blower motor resistor cannot be repaired and, if faulty or damaged, it must be replaced.