Circuit Operation

The Blower Motor circuit employs the following components:
^ Blower Motor
^ Blower Resistor Assembly
^ Blower Motor Relay
^ Heater:
- A/C and Rear Defogger Control Assembly
- Blower Switch
- Mode Selector

With the Ignition Switch in the RUN position, battery voltage is applied to the Mode Selector. The Mode Selector energizes the Blower Motor Relay when any selection except the OFF position is made. The Blower Motor Relay in turn sends battery voltage to the Blower Motor. The Blower Motor's speed is controlled through its ground. With the Blower Switch set to the 1 position, the Blower Resistor limits the voltage to the Blower Motor, thereby slowing it down. When the Blower switch is set to the 2 or 3 position, the operation is similar to the operation in the I position, except the resistance is incrementally decreased allowing more voltage to the Blower Motor. In the 4 position, the Blower Switch allows full battery voltage at the Blower Motor, by bypassing the Blower Resistor. The Blower Motor then runs at high speed.