C 2500 Truck 2WD V8-6.5L DSL Turbo VIN S (1997)
Radiator Cooling Fan Motor: Description and Operation
Auxiliary Cooling Fan operating Voltage is available at all times from the 30 Amp AUX FAN Mini-Fuse located in the Underhood Fuse-Relay Center.
Voltage is provided from the Fuse through the ORN (1540) wire which terminates at Pin 30 of the Auxiliary Cooling Fan Relay. When the Relay's Coil
is energized, Relay contacts close to apply operating Voltage to the Auxiliary Cooling Fan Motor. The RED (702) wire connects Relay Pin 87 to Motor
Pin B. The Motor is grounded from Pin A by the BLK (250) wire to Ground G112.
Voltage to the Auxiliary Cooling Fan Relay Coil is available when the Ignition Switch is in RUN and START. Relay Coil Voltage is supplied at Pin 85
by the PNK (639) wire from the 10 Amp A/C COMP Mini-Fuse located in the Underhood Fuse-Relay Center. The Auxiliary Cooling Fan Relay Coil is
energized by the VCM.
The VCM energizes the Auxiliary Cooling Fan Relay by grounding circuit 473 when Engine Coolant Temperature reaches a set point or when the
maximum, REC, A/C is requested by the vehicle operator through the Heater and A/C Control Module.