my fan went off .but it came on and off when i went over bumps it felt like it was a bad connection. so i went in through the glove box were there was some kind of censor fitted to the top of the duct Itook it out looked under it and taped it with a screw driver it sparked on one of the soldered joints . i soldered it up. job done, it may not be the same problem as yours but its worth knowing
chris
May 2008