Blower Control

Battery voltage is supplied with the ignition switch in RUN to Terminal A2 of the High Blower Relay through RED (542) wire. When the Heater and A/C Control Module is OFF, the High Blower Relay is de-energized. In this state there is no voltage path through the relay contacts to the Blower Motor so the Blower Motor does not run.

With the Heater and A/C Control Module in Low, Terminal E, CKT 60, of the Heater and A/C Control Module supplies voltage through the closed contacts of the Low Blower Relay and the three Blower Resistors to the Blower Motor. The Blower Motor is a variable speed motor which runs at a speed proportional to the voltage supplied to the Motor With all three Blower Resistors in the circuit. the supplied voltage is low and the Blower runs slowly.

In either of the Medium blower speed positions. MED1 or MED2, Terminal D (TAN, MED1) or C (LT BLU, MED2) of the Heater and A/C Control Module supplies voltage through the de-energized High Blower Relay and either one or two of the Blower Resistors allowing the Blower Motor to operate at increased speed.

With the Heater and A/C Control Module in High, the High Blower Relay is energized. The voltage path is then through the normally closed contacts of the High Blower Relay to the Blower Motor. With battery voltage supplied directly to the Motor, it runs at maximum speed.