For 1990-2009 cars

When the ignition switch is in RUN, battery voltage is supplied to the mode selector switch of the heater and A/C control . When the mode selector switch is in any position but OFF, voltage is supplied to the fan switch of the heater and A/C control.

The fan switch and the blower resistor assembly work together in order to determine the amount of voltage that is supplied to the blower motor. The blower motor is a DC motor whose speed is proportional to the input voltage.

With the blower switch in LO, the following actions occur:

• | All 3 blower resistors are in the blower circuit.

• | The blower runs at the slowest speed.

With the blower switch in M1, the following actions occur:

• | The blower switch bypasses 1 resistor.

• | The blower runs faster.

With the blower switch in M2, the following actions occur:

• | The blower switch bypasses 2 resistors.

• | The blower runs even faster.

With the blower switch in HI, the following actions occur:

• | The blower switch bypasses the blower resistor.

• | The blower switch supplies voltage to the blower relay coil.

• | Battery voltage is supplied directly to the blower motor.

• | The blower runs at maximum speed.