Radiator Cooling Fan Motor: Testing and Inspection

Fig. 035 - Chart C-12A - Coolant Fan Check.:

Fig. 036 - WIRING DIAGRAM for Chart C-12A Coolant Fan Check. VIN W:

CHART C-12A (1 OF 3)

FAN CONTROL CIRCUIT

2.8L SERIES

FUEL INJECTION (PORT)

a. The cooling fan is controlled by the ECM based on inputs from the coolant sensor and fan switch. The fan should run if coolant temperature is greater than 112°C. (234°F
b. Battery voltage is supplied to the fan relay on terminal E and ignition voltage to terminal C.
c. Grounding CKT 335 (relay terminal B) will energize the relay and supply battery voltage to the fan motor.
d. The ECM will remove the ground to CKT 335 if vehicle speed is over 40 MPH/
e. The Fan override switch will also ground CKT 335 if the ECM fails.
f. When A/C is used, the fan control switch mounted in the compressor will open when head pressure exceeds 233 psi (1600 kPa) and this input causes the ECM to ground circuit 335.
g. If a code 14 or 15 sets, the ECM will turn on the cooling fan.
Note: On STE Series CKT 335 will be grounded by the A/C control head when in the A/C mode.

Fig. 036 - WIRING DIAGRAM for Chart C-12A Coolant Fan Check. VIN W:

Fig. 038 - Chart C-12B - Coolant Fan Inoperative (2 of 3):

CHART C-12B (2 of 3)

FAN CONTROL CIRCUIT

2.8L SERIES

FUEL INJECTION (PORT)

a. The cooling fan is controlled by the ECM based on inputs from the coolant sensor and fan switch. The fan should run if coolant temperature is greater than 112°C (234°F).
b. Battery voltage is supplied to the fan relay on terminal E and ignition voltage to terminal C.
c. Grounding CKT 335 (relay terminal B) will energize the relay and supply battery voltage to the fan motor.
d. The ECM will remove the ground to CKT 335 if vehicle speed is over 40 MPH/
e. The Fan override switch will also ground CKT 335 if the ECM fails.
f. When A/C is used, the fan control switch mounted in the compressor will open when head pressure exceeds 233 psi (1600 kPa) and this input causes the ECM to ground circuit 335.
g. If a code 14 or 15 sets, the ECM will turn on the cooling fan.
Note: On STE Series CKT 335 will be grounded by the A/C control head when in the A/C mode.

Fig. 036 - WIRING DIAGRAM for Chart C-12A Coolant Fan Check. VIN W:

Fig. 041 - Chart C-12C - Fan Runs At All Times. (3 of 3):

CHART C-12C (3 of 3)

FAN CONTROL CIRCUIT

2.8L SERIES

FUEL INJECTION (PORT)

a. The cooling fan is controlled by the ECM based on inputs from the coolant sensor and fan switch. The fan should run if coolant temperature is greater than 112°C (234°F).
b. Battery voltage is supplied to the fan relay on terminal E and ignition voltage to terminal C.
c. Grounding CKT 335 (relay terminal B) will energize the relay and supply battery voltage to the fan motor.
d. The ECM will remove the ground to CKT 335 if vehicle speed is over 40 MPH/
e. The Fan override switch will also ground CKT 335 if the ECM fails.
f. When A/C is used, the fan control switch mounted in the compressor will open when head pressure exceeds 233 psi (1600 kPa) and this input causes the ECM to ground circuit 335.
g. If a code 14 or 15 sets, the ECM will turn on the cooling fan.
Note: On STE Series CKT 335 will be grounded by the A/C control head when in the A/C mode.