Operation CHARM: Car repair manuals for everyone.

Medium Blower Speeds

When the Medium 1 (M1) blower speed is selected, the HVAC control assembly applies voltage to the blower motor resistor assembly through the medium 1 blower motor control circuit. Voltage is divided between 2 series resistors and the blower motor to achieve the desired blower speed. The blower motor is included in the series circuit by the blower motor supply voltage and ground circuits. The blower motor resistor assembly provides a pathway to ground for the blower motor.

When the Medium 2 (M2) blower speed is selected, the HVAC control assembly applies voltage to the blower motor resistor assembly through the medium 2 blower motor control circuit. Voltage is divided between a series resistor and the blower motor to achieve the desired blower speed. The blower motor is included in the series circuit by the blower motor supply voltage and ground circuits. The blower motor resistor assembly provides a pathway to ground for the blower motor.