Im having the same issue on my 02 mounty. At first I thought it was related to broken wire harness in driver door. Thanks to all the guys n gals on here i fixed that without breaking a sweat. Yet the fuse hase blown again. Ive checked the track, cleaned the elec connections under set, made sure proper fuse was in, and no moister in fuse box. Still i have no luck with this issue. The fuse seems to blow on its own, meaning the switch does not have to operating at the time it blows. It also does not effect any other components in vehicle. Any one please, these fuses r getting costly trying to diagnose problem.