Primary Heating System

The blower switch provides a choice of four blower speeds "Lo," "Med 1," "Med 2" and "Hi." The blower switch receives power from the HTR and A/C fuse when the ignition switch is in the "ON" position.

In the "Lo" speed position, the circuit continues through the heater wiring harness to three resistors in the blower motor resistor relay.

In the "Med 1" speed position, the circuit continues through the heater wiring harness to the blower motor resistor relay, but it bypasses one of the three resistors.

In the "Med 2" speed position, the circuit continues through the heater wiring harness to the blower motor resistor relay, but it bypasses two of the three resistors.

In the "HIGH" speed position, the circuit continues through the heater wiring harness to the blower motor resistor relay, but it bypasses all three resistors and closes the relay's normally open contact to provide full power to the blower motor from the HVAC maxifuse(R).

From the blower motor resistor relay, the circuit goes to the blower motor terminal. The blower motor circuit is completed to ground by a wire in the heater wiring harness that goes from the blower motor terminal to the generator or A/C compressor bracket.