Le Mans 2 battery charge / light glitch-update.

[wirespokes]

I'm a little slow getting to this one, but the volt meter dropping to zero told me 'ignition switch'. If the alternator was faulty, voltage wouldn't have dropped to zero. Usually the bike will run till voltage drops below 10V or so.

These switches are known to be a problem. Pretty common. One of the first places to look.

[Bazil]

I had this on my Mark IV LeMans. Turned on the headlight, voltmeter went to zero, charge light went on ( and no headlight). Turned off the headlight and all was fine. Lots of potential points of failure to look for.

After lots of futzing around traced it to a faulty lampholder in the instrument cluster - the one that shows when the headlight is on. Replaced the lampholder with a new one ( T10 wedge) soldered in. No further problems.

Another rabbit hole to go down !

Good luck.