RAM 2500 Truck 4WD V10-8.0L VIN W (1997)
Blower Motor: Description and Operation
Circuit Operation
CIRCUIT OPERATION
When the ignition switch is in the RUN position, circuit C11 from the blower motor relay provides voltage to the blower motor.
From the blower motor, circuit C7 splices to the blower motor resistor and the A/C-Heater control switch.
The ground path for the blower motor is through the circuits that connect from the blower motor resistor block and then through the fan switch in
the A/C heater controls to circuit Z3. The blower motor resistor block consists of three resistors connected in series.
Each resistor in blower motor resistor block is spliced to the fan switch on separate circuits; C4, C5, C6, and C7. Depending on fan switch
position, voltage passes through one or more resistors to ground. Blower motor fan speed is controlled by the number of resistors voltage passes
through to ground.
When the fan switch is in the LOW position, circuit C4 provides the ground path. In the M1 position, circuit C5 provides ground. In the M2
position, the ground path is through circuit C6. Circuit C7 provides path for ground when the switch is in the HIGH position.
