Medium Blower Speeds

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

When the Medium 1 (M1) blower speed is selected, the HVAC control module applies voltage to the blower motor resistor assembly through the medium 1 blower motor control circuit. Voltage is divided between 3 series resistors a blower relay, 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 module applies voltage to the blower motor resistor assembly through the medium 2 blower motor control circuit. Voltage is divided between 2 series resistors, a blower relay, 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 3 (M3) blower speed is selected, the HVAC control module applies voltage to the blower motor resistor assembly through the medium 3 blower motor control circuit. Voltage is divided between a series resistor, a blower relay, 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.