For 1990-2009 cars

The blower motor circuit employs the following components:

• | The blower motor

• | The blower resistor relay

• | The blower motor relay

• | The heater A/C control assembly

• | The blower switch

When the ignition switch is in the RUN position, battery voltage is applied to the blower switch.

When the blower switch is set to LOW, battery voltage is applied to the blower motor through the blower resistor assembly and the normally closed contacts of the blower motor relay. The blower runs at a low speed.

When the blower switch is in the M1, M2, or M3 position, the operation is similar to the operation in LOW with the following exceptions:

• | The resistance through the blower resistance assembly is decreased at each step.

• | The decreased resistance causes the blower motor to run faster in the M1, M2, and M3 position.

When the blower switch is turned to HIGH, the blower switch applies voltage to the blower motor relay coil. The blower motor relay is energized. This condition applies voltage from CKT 2140 through the relay directly to the blower motor. The blower motor then runs at a high speed.