HVAC System - Manual

HVAC BLOWER CONTROLS CIRCUIT DESCRIPTION
The Blower Motor is a variable speed motor. The higher the voltage applied to the motor, the faster the speed. Battery voltage to the Blower Motor is supplied by the Heater-A/C Control by way of the Blower Motor Relay. At low and medium speeds, the voltage is steeped down by the Blower Motor resistors from the circuit. At high speed the Blower Motor relay is energized, removing the resistors from the circuit. Battery voltage is then applied directly to the Blower Motor through the relay. The motor will then run at maximum speed.