MODEL IDENTIFICATION
Vehicle model can be identified by fifth character of Vehicle Identification Number (VIN), stamped on metal pad on top of left end of instrument panel, near windshield. See MODEL IDENTIFICATION table.
| Series (1) | Model |
|---|---|
| "C" | 2WD Pickup, Sierra & Suburban |
| "G" | (2) Van |
| "K" | 4WD Blazer, Pickup, Sierra, Suburban & Yukon |
| "L" | AWD Astro & Safari |
| "M" | 2WD Astro & Safari |
| "P" | Commercial Van |
| "S" | 2WD Blazer, Jimmy, Pickup & Sonoma |
| "T" | Bravada, 4WD Blazer, Jimmy, Pickup, Sonoma & Typhoon |
| (1) Vehicle series is fifth character of VIN. (2) Includes Rally Van and Vandura. | |
| (1) | Vehicle series is fifth character of VIN. |
| (2) | Includes Rally Van and Vandura. |
MODEL IDENTIFICATION
| Application | Engine |
|---|---|
| "C", "G", "K" & "P" Series | All with A/C |
ELECTRIC COOLING FAN APPLICATION
DESCRIPTION
On "C", "G", "K" and "P" Series, electric cooling fan is an auxiliary cooling unit for A/C condenser.
"C", "G", "K" & "P" Series
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 temperature 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 cooling fan is on, and the coolant temperature sensor is above the set temperature.
Switch is located on right cylinder head, above center of exhaust manifold. On "G" and "P" Series, relay is located in engine compartment on center of firewall. On "C" and "K" Series, relay is mounted to left inner fender, near engine compartment firewall.
TROUBLE SHOOTING & TESTING
Note. For information on electric cooling fan trouble shooting and testing, see appropriate SYSTEM/COMPONENT TESTS article in ENGINE PERFORMANCE section. (Scheme 1)
Scheme 1
Cooling Fan Relay (Removal & Installation)
- Disconnect negative battery cable.
- Disconnect wiring harness connector. (Scheme 2)
- Remove the relay from the inner fender.
- To install, reverse removal procedure.
Coolant Temperature Sensor (Removal & Installation)
- Disconnect negative battery cable.
- Disconnect wiring harness connector. (Scheme 2)
- Using socket, remove coolant temperature sensor. (Scheme 2)
- To install, reverse removal procedure. Tighten sensor to 17 ft. lbs (23 N.m). Add necessary coolant to fill system.
Auxiliary Coolant Fan (Removal & Installation)
Note. A removal & installation procedure is not provided by manufacturer. (Scheme 2)
Scheme 2
Coolant Fan Relay (Removal & Installation)
- Disconnect negative battery cable.
- Disconnect wiring harness connector. (Scheme 3)
- Remove relay retaining screws and remove relay from cowl panel. (Scheme 3)
- To install, reverse removal procedure.
- Disconnect negative battery cable.
- Disconnect wiring harness connector. (Scheme 3)
- Using socket, remove coolant temperature sensor. (Scheme 3)
- To install, reverse removal procedure. Tighten sensor to 17 ft. lbs (23 N.m). Add necessary coolant to fill system.
- Disconnect negative battery cable.
- Remove the grille assembly.
- Disconnect wiring harness connector. (Scheme 3)
- Remove the bolts and nuts for the auxiliary fan assembly, and remove fan.
- To install, reverse removal procedure. Tighten nuts to 115 INCH lbs. (13 N.m). Tighten bolts to 42 INCH lbs. (4.7 N.m).
Scheme 3
Cooling Fan Circuit Wiring Diagram("C" & "K" Series - 7.4L). Scheme 4
Cooling Fan Circuit Wiring Diagram ("G" Series - 7.4L). Scheme 5
Note. Cooling fan circuit diagram is not available for "P" Series vehicles.
See also:
• MODEL IDENTIFICATION