Blower Motor: Description and Operation

CIRCUIT OPERATION
With the ignition switch is in the RUN position, power flows from the 30 Amp fuse located in the junction block, cavity 1, to the blower motor. Blower motor speed is controlled by the fan control switch located in the A/C-Heater control head, and by the resistor block.

Blower motor LOW speed operation is accomplished on the C4 circuit. When the control switch is moved to the LOW speed position, current flows from the C1 circuit to the blower motor resistor. Power flows through the blower motor back to the resistor. Voltage is passed through the resistor to circuit C4. Circuit C4 connects from the resistor block to the fan control switch. Ground flows through the switch to the Z1 circuit. The Z1 circuit terminates at a grounding point located at the instrument panel.

The operation of blower motor M1 and M2 speed operations is the same as the LOW speed except that circuit C5 is used for the M1 speed, and circuit C6 is used for the M2 speed operation.

Blower motor HIGH speed operation is accomplished on the C7 circuit. There are no resistors used in the HIGH speed mode.