Hi,
You could try to isolate the electrical functions vs riding with some static tests
1) Replace the fuse.
2) Turn on the ignition, don't start the engine.
3) Taillight is on?
4) Pull the Brake - Brake light on?
5) Left / Right turn signals - check each
6) Horn
If you pop the fuse on any of the tests - you have narrowed it down.
No popped fuse?
7) Start the engine

Headlight on? - Yes - good, it a quick stator charge coilcheck. No - check charge coil and regulator (some regulator failures take out the charge coil)
9 ) Turn off engine, turn ignition back on
you should see the taillight - if not - check fuse - popped? Yes - check regulator.
10) None of the above caught the problem? Hmm, maybe there's some worn insulation and intermittent shorting going on. Visually inspect harnesses where they rub on metal or other harnesses.