usually the voltage reg. is the root cause of this.
Thanks for helping me think it through. Things will remain as they are for a week or more, until I have to ride at night again.
I'll update this, as I go through whatever is happening. I might be able to grab an oscilloscope shot of the DC voltage at the battery at work this week. It would be nice to know how much AC ripple is acceptable on the DC, to Kawasaki.
It's not the most complicated system on the bike. The part that is making it somewhat difficult to troubleshoot is only being able to observe the fault at night, in motion. This is why I am leaning towards a shorting wire, dirty contacts, or a munged up switch.
When the high beam goes dim,it does not seem to affect the low beam. Nor does it seem to go completely out--just browns out to almost no high beam.
If it's the r/r, I'd expect problems when the available current is low -- idle speed being the worst. I would also expect to be having charging problems. None so far.
The regulator has to be working at low load conditions, as the voltage at 5K and idle remained at 14.6. With the increase in load adding the second bulb @ 55 Watts, I'd expect the voltage to sag slightly. 14.3 at idle and at 5K seems to indicate the r/r is doing business as usual.
I have considered melted insulation that allows a short when hot, thought about a nearly dead high beam bulb that sh*ts itself with vibration, and of course the idea that the r/r might be bad.