While I was disassembling my rear fender to paint it, I noticed that the wiring holes through which the wire passes from under the fender into the taillight assembly were mismatched. The wires were being pinched between the metal fender and taillight assembly. I enlarged the fender hole to more closely match the taillight assembly hole and wrapped more black tape around the wires before reassembly. I also noticed the wiring connector (under the seat) was blue-green powdery with corrosion so I cleaned those terminals with WD-40, greased them with dilectric grease, and pressed them together. Trust what your fuse is telling you; don't kill the messenger.