Testing Procedures

Electric Fan Motor (Typical).:

ELECTRIC FAN MOTOR TEST PROCEDURE

To check out the electric fan motor, disconnect the fan motor wire connector and connect it with #14 gage wires to a good 12-volt battery observing correct polarity per figure. If the fan runs normally, the motor is functioning properly. If not, replace motor. If the motor is noticeably overheated (i.e.; wire insulation melted, motor charred) the system voltage may be too high. Check charging system.

SMEC (Engine Controller) 60-Way Connector From Terminal End:

RADIATOR FAN MOTOR CONTROL TEST PROCEDURE
(Fan Relay and SMEC Operated)

Equipment Required
^ Diagnostic Tool C-4850 or equivalent
^ Volt/Ohm Meter
^ Wiring Diagrams.


1. Bring the engine to normal running temperature.

2. Check wiring connector in C25, C9. and C26 for proper engagement, see Wiring Diagrams.

3. Using a diagnostic tool, plugged into the diagnostic connector rearward of the battery, check the On-Board Diagnostics (OBD) in the Single Module Engine Control (SMEC) for fault codes.

4. If fault code 88-12-35-55 is detected. proceed to Step 5.

5. With the ignition switch in the run position, test for battery voltage at single pin connector at the fan relay.
^ Voltage reading OK. proceed to Step 6a.
^ Voltage at 0-1 volt, proceed to Step 6b.

6a With the ignition OFF, disconnect the 60-way connector from the SMEC (outboard of battery) and return the ignition to the RUN position. Test for battery voltage at cavity 31 of the 60-way connector.
^ Voltage reading OK and female terminal is not damaged, replace the SMEC.
^ Voltage reading 0. repair open or short in C27 circuit.

6b With the ignition off, disconnect the 60-way connector from the SMEC (outboard of battery) and return the ignition to the RUN position. Test for battery voltage at the single pin connector at the fan relay.
^ Voltage reading OK. replace the SMEC.
^ Voltage reading 0-1 volt. proceed to Step 7.

7. With ignition in the run position. test for battery voltage at the blue wire (C27) in the 3-way connector of the fan relay.
^ Voltage reading OK. replace the fan relay.
^ Voltage reading 0. repair open or short, in C27 circuit

8. Turn ignition off, connect the 60-way connector at the SMEC, and test the system.