Electrical problems, especially intermittent electrical problems, seem to be the toughest problems for most people who work on cars, bikes, appliances, etc.. I don't know if that is due to insufficient training, the lack of incentive or motivation to take the time to study the system and think through the areas that could cause the symptoms and then to trace those circuits for anomalies, or what. What I do know is that the auto dealerships I used to visit as part of my job back in the day would kiss the butt of a truly gifted electrical diagnostician and do whatever it took to keep them. They are a rare breed.
These kinds of problems quickly expose the "parts changers" that so heavily populate dealerships these days. Thus all the horror stories of five and ten or even more attempts to fix problems. I know the auto industry has been trying to find ways to address this problem; it's way past time for Harley to step up and do the same.
Jerry