There are usually only three reasons for the Cooling Fan not working...
1) The Radiator Fan Motor is bad... To test remove the Fan Relay using a test light ground the clip end to a good ground. Then probe each socket making sure to remember which ones light up. After that using a jumper wire plug one end into one of the hot sockets, the ones that lit up the test light, then plug the other end into one of the sockets that Did Not Light Up. If fan doesn't come on try next socket and so on till you have jumped all sockets that did not light the test light. If fan come on you know that the fan is obviously good and your problem lies with one of the following items.
2) The Coolant Temp Sensor... It is located at the rear of the engine about center way... If this is bad then usually your engine light is on.
3) The Radiator Fan Relay gone bad... It is located in the power box under the hood. Check out the link below for testing...
Saturday, April 11th, 2009 AT 5:10 PM