Blower Control

BLOWER MOTOR
The Blower Motor is a variable speed motor. The higher the voltage applied to the motor, the faster the speed.

With the Heater-A/C Control in "OFF," voltage is applied to the Blower Motor Low Speed Relay coil. The relay is energized and no voltage is applied to the Blower Switch or the Blower Motor.

When any other mode except "OFF" is selected, the Blower Motor Low Speed Relay is de-energized and voltage is applied to the Blower Switch and Blower Motor Resistor.

When the Blower Switch is in "LO," voltage is applied through the Blower Motor Resistor and the Blower Motor High Speed Relay to the Blower Motor. The Blower Motor runs at low speed.

As the Blower Switch is moved through positions "M1" and "M2", the switch bypasses part of the Blower Motor Resistor, allowing more voltage to be applied to the Blower Motor, which will increase its speed.

When the Blower Motor Switch is in "HI," voltage is applied to the coil of the Blower Motor High Speed Relay. The Blower Motor High Speed Relay is energized removing the Blower Motor Resistor from the circuit. Battery voltage is then applied directly to the Blower Motor though the Blower Motor High Speed Relay contacts. The motor runs at maximum speed.

AUXILIARY BLOWER MOTOR
The Auxiliary Blower Motor is also a variable speed motor. With the Ignition Switch in "RUN" and the Heater-A/C Control in "OFF," voltage is applied to the Blower Motor Low Speed Relay coil. The relay is energized and voltage to the Auxiliary Heater-A/C Blower Motor Relay is removed. No voltage is supplied to the Auxiliary Blower Motor. When any other mode except OFF" is selected, the Blower Motor Low Speed Relay is de-energized and voltage is applied to the Auxiliary Heater-A/C Blower Motor Relay. The Auxiliary Heater-A/C Blower Motor Relay is energized and voltage is applied to the Auxiliary Blower Motor from the R BLW Fuse. The ground for the Auxiliary Blower Motor is controlled by the Auxiliary Blower Switch.

When the Auxiliary Blower Switch is in "LO" or "MED," voltage is applied through the Blower Motor, and all or part of the Auxiliary Blower Motor Resistor to ground. When the Auxiliary Blower Switch is in "HI," the resistor is bypassed and the Blower Motor connected directly to ground, to run at high speed.


AUXILIARY BLOWER SWITCH AND AUXILIARY BLOWER CONTROL
The Auxiliary Blower Control and the Auxiliary Blower Switch control the fan speed of the Auxiliary Blower. Both are wired in parallel and have the same function except that the Auxiliary Blower Switch must be in the "RR CTRL" position for the Auxiliary Blower Control to be operational.