If you have the tools to do electrical testing I would test the fan relay (on the frame in front of the battery) and the Fan Timing Control Unit (under the pass. side dash). I replaced both on my car but it turned out to be the Fan Timing Control Unit. If you are handy with a solder gun you can also just take out the Fan Timing Control Unit and resolder all the contacts. This is probably more economical because a new one costs $130. HTH