The Engine Coolant Temperature Switch (when disconnected) will run the fan all the time. That is one procedure you can use to test the fan.
Either the switch fan is not making proper contact or a relay is stuck.
I would clean the fan switch with electronics cleaner and the connector, to assure they are making proper contact. The fan relays are in the engine compartment marked 1 and 2.
If that doesn't work, disconnect the negative battery cable and clean the fan relays and the main engine relay and blow any water or contamination out.
Make sure the AC switch is not on.
Wednesday, June 4th, 2008 AT 4:25 AM