1. To test a fan motor, unplug the electrical connector at the motor and use fused jumper wires to connect battery power and ground directly to the fan. If the fan does not operate, replace the motor.
2. If the motor tests OK, check the cooling fan thermo switch, located at the bottom of the radiator on the driver's side.
3. Remove the electrical connector from the cooling fan thermo switch and apply a fused jumper wire between terminals number 1 and number 2 with the ignition switch in the ON position, with the engine not running. Both engine cooling fans should run at low speed.
4. Next apply the fused jumper wire between terminal number 2 and number 3 with the ignition switch ON and the engine not running. Both engine cooling fans should run at high speed.
5. If the fans run as described in steps 3 and 4, it indicates that the cooling fans and circuits are running properly and the thermo switch is faulty.
6. If the fans do not operate with the thermo switch bypassed, check for voltage at the red wire of the thermo switch electrical connector. There should be battery voltage.
7. If voltage is not present check the large cooling fuses in the engine compartment fuse holder and the No. 16 fuse in the passenger compartment fuse box. If the fuses are OK, the problem lies in the wiring harness, the fan control module or the coolant temperature sensor.
8. Check the wiring for open or short circuits. The fan control module can only be diagnosed as faulty through process of elimination.