Auxiliary Cooling Fan Replacement - GMC G Service Manual

6B1-32 ENGINE COOLING
AUXILIARY COOLING FAN
REPLACEMENT
The Auxiliary Cooling Fan provides additional cooling at
low speed vehicle operations, extended idle, stop and go
conditions, and when running the air conditioning system.
The auxiliary cooling fan circuit consists of a coolant
temperature sensor, a relay and the auxiliary fan. When the
coolant sensor reaches a predetermined temperature, it
closes the circuit to the relay coil, which energizes the relay,
passing 12 volts to the auxiliary fan. When the coolant tem­
perature decreases below the setpoint of the sensor, the
circuit to the relay opens and 12 volt power to the auxiliary
fan stops. The cooling fan only operates when the ignition is
on and the coolant temperature sensor is above the set
temperature.
Refer to figure 46 for the auxiliary cooling fan circuit
diagram, and to figure 47 for auxiliary cooling fan system
diagnosis.
A. 1st Track
B. 2nd Track
C. 3rd Track
D. 4th Track
50. Water Pump Pulley
51. Crankshaft Pulley
52. Generator Pulley
53. A.I.R. Pump Pulley
54. Power Steering
Pump Pulley
55. Air Conditioning
Compressor Pulley
56. Idler Pulley
Figure 42 — Engine Accessory Drive — Heavy Duty Emissions 5.7L Engine (P-Models)
COOLING FAN ASSEMBLY
M Remove or Disconnect (Figures 48 and 49)
1. Grille assembly. Refer to SHEET METAL (SEC. 2B).
2. Fan harness connector (83).
3. Bolts or screws (82).
4. Fan assembly (81) from the radiator support (80).
B Install or Connect (Figures 48 and 49)
1. Fan assembly (81) to the radiator support (80).
2. Bolts or screws (82).
I ^ l Tighten
• Bolts or screws (82) to 6 N«m (53 ft. lbs.).
3. Fan harness connector (83).
4. Grille assembly. Refer to SHEET METAL (SEC. 2B).
F-00913