Just an update on this. I decided to go ahead and complete what was headed toward a mini-electrical overhaul anyhow so here is how it stands now:
Has new :
(*) Modern regulator/rectifier from Rick's. It's mounted where the old rectifier was.
(*) Has a new EMGO stator which supposedly puts out more voltage than the original. And it WAS when I measured the voltage after
installing it last week.
(*) As part of the new reg/rec install, the 4 Plug "electrical panel" under the left side cover really is no longer needed so it was easy to remove.
(*) To get rid of old wiring that was chafing on the edges of the entrance hole where it went from the right handlebar control THRU the bar
into the headlamp area, a new switch with new wiring running on the outside of the bar was installed.
(*) The original 3-[glass]fuse box was replaced with a modern ATM panel
(*) Installed a relay setup to power the coils using the original wires as the relay switch.
(*) Installed a dual relay setup for the headlamp using the original bulb plug wires to switch the relays.
(*) Got rid of the "Aux Lighting" unit.
(*) New lithium battery. This was more or less a last desperate 'swing in the dark' . Sometimes batteries do weird things- but, unsurprisingly,
the battery was not the problem.
So I've taken it on 3 short rides since buttoning it back up yesterday.. The thing doesn't miss a beat. The headlamp is bright again but that's where the good news ends. At the end of a 10 or 15 minute ride, the battery shows a 10th or 2/10ths volts lower than before the ride began. A couple more short rides and it will need a recharge. Same as the end of last season before all this work was started. The voltage regulator gets pretty hot but not sure it isn't supposed to and there seem to be no relays, fuses, or wiring that are unreasonably warm. The one monster "clue" I've been seeing IS that when you test voltage at the battery, it seems normal and charging about 13.2 volts at idle with the headlight OFF.. As soon the headlight is switched on, voltage reading at the battery drops to 12.9 and slowly keeps falling by 10ths. When the light is shut off, the voltage
climbs. Pulling the bulb but leaving the switch ON has the same effect as shutting the switch off, eliminating the taillight and running lights as
suspects. Switching beams doesn't produce any changes so the issue must be somewhere in the high/low beam power feed circuit?
You'd think the fuse or headlamp wiring to/from the box would be warm but it is not. I am stumped.