System Diagnosis

1. Start and run engine, ensure that engine coolant temperature is below 199°F. If fan does not operate proceed to step 3.
2. If fan operates, disconnect fan switch connector. if fan stops running, replace fan switch. If fan continues to run, repair short to voltage in blue wire between fan switch and fan motor.
3. Run engine until coolant temperature is above 208°F. If fan operates, system is functioning properly.
4. If fan does not operate, disconnect fan switch connector and connect a fused jumper wire between cavities 1 and 2. If fan operates, replace fan switch.
5. If fan does not operate, turn ignition switch to Off position. Disconnect fan motor connector and connect a suitable digital ohmmeter from cavity 1 to ground and measure resistance.
6. If resistance is greater than .3 ohms, repair black wire between fan motor and ground G101.
7. If resistance is less than .3 ohms, backprobe fan motor connector with a suitable test lamp from cavity 2 to ground. If test lamp lights, replace fan motor.
8. If test lamp does not light, connect test lamp from fan switch connector cavity 1 to ground. If lamp lights, repair open in blue wire between fan switch and fan motor. If lamp does not light, repair open in black/white wire between fan switch and junction block.