With Manual Controls

The Blower Motor is a variable speed motor; the higher the voltage applied to the motor, the faster the speed. With the Heater/Vent/Air Conditioning (HVAC) Control Head placed in any position except "OFF," current flows from the A/C Clutch Fuse through the HVAC Control Head, energizing the Low Blower Relay. This supplies current to the Blower Switch and Blower Motor Resistors. When the Blower Switch is in "HI," current flows through the Blower Switch energizing the High Blower Relay. This supplies the Blower Motor with battery voltage for maximum speed.

When the Blower Switch is placed in "LO," current flows through the Low Blower Relay coil and voltage is applied to the Blower Motor Resistors. This reduces the amount of voltage applied to the High Blower Relay which feeds the Blower Motor.

When the Blower Switch is placed in "MED 1" or "MED 2", current flows through the Low Blower Relay contacts to the Blower Switch, which applies current to a different resistor within the Blower Motor Resistor block. This increases or decreases voltage to the Blower Motor, depending on Blower Switch position.