I have a 99 F150 and when the doors are closed and I replace the fuse, the windows, mirrors and interior lights work. The minute I open the door, the fuse blows. How can I fix this?

 

It sounds like one of your dome or door lights is shorted to ground. When you open the door, the light tries to turn on and it shorts. I'd check from the bulbs and then work backwards until you find a pinched wire somewhere. Often the culprit is in the black rubber wire tube between the door and the body of the truck.

Good luck.