Battery light flickers on and bike cuts out sometimes

[NortonDave]

So my problems began with the starter motor not stopping which was a stuck relay. I've replaced the relay and fully charged the battery (lithium) and that seems fine. Then out on first ride the battery light on the dash sometimes flickers on and off but kept running also  sometimes the motor just cuts out?
I'm suspicious of the ignition key barrel? I've also been told it could be the starter motor brushes creating a short?

[frankenduck]

K1 or K75?

[Laitch]

It's the K75. He posted about the first problems April 14.

[frankenduck]

I vote dirty ignition switch or maybe a loose ground. Usual symptom of dirty starter is turn signals behaving abnormally.

[NortonDave]

Yes 1985 K75, 40 years old and still puts a smile on my dial. Yep think you're right, I've just pulled the key barrel apart and cleaned the connecting surfaces and luckily it went back together, looking good so far after 10 km test ride. Warning to others though it's a fiddly job and could've easily gone pear shape. I see a new one on motobins is 190 pounds sterling!

[daveson]

I had a similar problem with similar symptoms . The earlier symptom was that everything was Ok except that the battery light was on, but only faintly. It was only noticeable at night time. If you don't ride at night, check the light at night time. If it's still on, the problem might be related to the alternator, then check the voltage across the battery at idle and revs and higher revs.

If the alternator is ok, it could be a problem with power to the load shed relay. In my case it was worn starter motor brushes. If the load shed relay isn't getting earth from the starter motor, there will be no power at fuse seven, so, as mentioned, the turn signals will behave wonky, similar to hazard lights. Also, for example, the horn won't work. If the load shed relay isn't getting power from the ignition switch, again there will be no power to fuse seven, with the same symptoms as previously. If the problem returns and the alternator is good, turn the ignition switch on. You should then hear a faint click from the load shed relay, which varifies that the ignition switch is sending power to the load shed relay. Then the starter motor is suspect. If no click, the ignition switch is suspect. If the problem returns while riding, one check would be to see if the horn is working.