I have the same problem with my girlfriends 98 Mystique LS 2.5L. The fuse for the fan blows at any given time if it is working extra than normal. I am not 100% sure if the setup is the same in both vehicles, but the fuse is located in the power distribution box located at the drivers side front engine compartment next to the battery (on mine). It is not a standard looking fuse but rather a large yellow (color could vary)box type with a see through top. On mine there is a clip at the front of the three bar fuse strip that you push and that unit raises up slightly. There is two bolts you would have to remove underneath that panel for fuse removal. If you have your manual still it will tell you where tolocated this power distribution box and the proper fuse. If it is the fuse mine ran about $3.00 at any Advanced Auto. As I said not sure if we have the same setup but hey it is worth a shot.
Rick
