1980 v50 II electrics

After returning from work on a very very wet day, turned off ignition took key out and the battery light stayed on even with all fuses removed  also on in park mode . No battery light  when ignition switched on. Bike starts and runs fine all electrics work fine . Removing the positive feed to the rectifier solves the problem but is no solution, noticed the wire and rectifier was very warm when i done this . Don’t know if this is an earthing problem or rectifier problem or if somethings had a melt down other than my brain. I’ve checked connections at headlight and under the tank, ignition switch all the switchgear and they seem fine. Anybody got any ideas as I’ve ground to a halt.

Sounds like a duff rectifier.
See if you can borrow one to change over.
After that check all your earth leads, this solves a lot of problems but probably not this one.
I am assuming you haven’t messed with the wiring in between working fine and not working.
If you have put it back as it was.
With electrical problems try one thing at a time and if it doesn’t solve the problem but things back as they were.
Remember electrics really are fun.

Yes sounds like current is flowing down to the generator rotor, this will make light glow when ignition off and not light when ignition on, because rotor brushes already have 12V across them. Note rotor takes up to 4 Amps so battery will quickly be discharged if left like that and probably accounts for the constantly hot wire etc. I’m assuming it’s the usual Bosch 3-phase alternator system

Electrics. Â Fun?1?1 :confused: Â Even for your often strange sense of humour that’s pushing it a bit, Ian. Why can’t you just see dragons like most of the population? I got a headache just trying to buy some domestic light bulbs this afternoon.
By the way, glad to hear you’re back riding. Take care. MaggiÂ

Robert, send me your email address via PM and I will send you a coloured wiring diagram that should help you sort out you problem. I’m not saying it will resolve the problem but when the colours of the wires on the bike match those on the diagram it helps to understand where they go.

Best wishes

Because the army spent a lot of money and 18 months teaching to fix complicated electrikery, and then paid me a large salary to go and fix said magic stuff.
I thouraghly enjoyed it.
Electrics are no more difficult to understand than most things once you lose your fear of them.