The front blower motor controls operate by supplying voltage to the motor through the switch and the relay contacts. Battery voltage is available from HTR-A/C fuse 12 when the ignition switch is in the RUN position to the heater and A/C controller through CKT 141 (BRN). This voltage is available to the blower switch of the heater and A/C controller, when the mode switch of the heater and A/C controller is not in the OFF position. This power is for operation of the front blower motor at the low and medium speeds only. This power also operates the blower motor relay in the blower motor resistor/relay. The relay energizes in order to operate the blower motor in the HI speed. Battery voltage is available at all times from the HVAC MaxiFuse® to the blower motor resistor/relay through CKT 542 (RED). The voltage is available for the operation of the front blower motor at high speed.

The blower motor switch in the LO position applies voltage from the switch contacts through CKT 60 (YEL) to the blower motor resistor/relay. The blower motor remains de-energized. The current flows through the three resistors and the normally-closed relay contracts to the blower motor. CKT 65 (PPL) pigtail wire provides operating voltage to the blower motor from the blower motor resistor/relay. Grounding the blower motor resistor/relay at ground G103 through CKT 150 (BLK) establishes a current flow. The voltage drop through the three resistors limits the motor operation to the lowest speed.

The blower motor switch in the medium 1 position applies voltage to the blower motor resistor through CKT 63 (TAN). The current must flow through only two resistors in order to reach the motor. With the increased voltage at the motor, the motor operates at a faster speed.

The blower motor switch in the medium 2 position applies voltage to the blower motor resistor relay through CKT 72 (LT BLU). The current must flow through only one resistor in order to reach the motor. With the increased voltage at the motor, the motor operates at a still faster speed.

The blower motor resistor has automatic reset thermal fuses for each resistor. These fuses automatically open with a high current flow. The current flow heats the fuse element. When the current stops, the fuse cools. The fuse then resets automatically.

The blower motor switch in the HI position applies voltage through CKT 52 (ORN) to the blower motor relay coil. Because the coil grounds at ground G103 through CKT 150 (BLK), the relay coil energizes. Energizing the relay coil closes the relay's normally-open contacts. Energizing the relay coil also applies voltage from HVAC fuse to the blower motor. Because the operating current bypasses the resistors, the blower motor operates at the highest speed.