Electrics problem

[tomo]

Took the bike out for a spin today, ran great. Got home and with engine idling, reversed into the garage (pedalling with my feet I hasten to add ) and engine cut out. Thought nothing of it as idling speed is a bit low, need to adjust, but then noticed no panel lights at all and electrics totally dead. Can`t recall if it cut when I turned the light switch off. Anyway, lifted the seat and took off side panels, checked the fuse and looks ok, fiddled about a bit with wires and when I moved the wire that runs from the reg/rectifier to the battery positive terminal, found the panel lights came on again and also started up again. Let it run a minute or so then turned the light switch on, bike died again and again electrics totally dead. Fiddled about with the wires again but no good. Electrickery ain`t my strong point, any ideas ?. Would a faulty reg/reg cause this ?. The bike is a 79 GS750. Battery is new and as I only recently stripped the bike down and rebuilt, I`m confident all connections & wiring are ok, even unwrapped the harness to check wires and re-wrapped. The reg/rectifier is a Honda unit fitted many years ago when I got the bike. Any suggestions/advice much appreciated.

[Rich82GS750TZ]

.....fiddled about a bit with wires and when I moved the wire that runs from the reg/rectifier to the battery positive terminal, found the panel lights came on again and also started up again...... I`m confident all connections & wiring are ok,.......Any suggestions/advice much appreciated.

Disclaimer: I’m a hobbyist, not a professional motorcycle mechanic nor electrical engineer, and what follows are opinions. Long story.

Breaking down your story to just the two statements above, it would seem you’ve isolated your issue to the red wire that comes from the RR to the battery, despite the claim in your second statement.

If you can get the bike running long enough, with the battery terminals exposed, and a volt meter handy, run the quick test linked in my signature, and report all six numbers. That will at least verify the health of your charging system. But I still believe you probably have an intermittent continuity problem in that red wire from RR to battery.