Rick, That's the puzzle. What was the last thing I did to the bike... Nothing. That's rules out disturbing things. So then you assume the parts inside the black box are built with heat parameters and pass this type of environment, i.e., sitting behind a hot engine, riding on a hot day. There you think the black box goes thru heat cycles thru its lifetime. You think what are the odds you rode it home and not a glitch when the key turned off.
What next would come to mind is taking a multi-meter and using this to see if the coil has 12v (+) at said wire side connection = What did you do mechanically we keep narrowing it down = Key switch??? See where I'm going? So if hot goes to coil, hot goes to the black box, if the coil wire has a piggyback and this jumps from coil to black box?
If we play the key switch game, taillight turns on with key on. Say you'd assume if the taillight goes on, why not the coil/box? I'm not familiar with the wiring setups/keyfob, etc., so I'll more explain it in the generic. Make a V sign with one hand. Make a fist with the other. Place fist into V fingers. See how the key internals has a ball kind of dual connection action? The ball touches two wires. One to the taillight, one to the coil:
1. Key assembly?
2. Wire off of key assembly?
3. Wire broken off key assembly?... (that's if no joy at the coil)