Sometimes the connection on the fuse may corrode a bit and cause an interruption of power even though it visually appears ok. If you haven't I would first try putting in a brand new fuse and seeing if that fixes the problem before you start looking deeper so that you may rule this out as a possibility or potentially fix your problem.
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record