1984 KZ1000P,I have been re-grounding each component, trying to isolate the gremlin that turns on and off at will each light on the motorcycle. The lights work one minute and the next time that I turn the ignition key, they don’t. Its maddening. I have spent hours and hours trying to find the offending connection. Has anyone had this issue, and what was the answer?
Use a wiring diagram and the guide in the below link, start at the consumer that isn't working and move backwards towards the power source until you find the point that you are losing voltage. Be methodical and logical and it will take hours not days to sort these issues (don't be tempted to short-cut the process)
It’s a retired police unit, so there’s wires everywhere. Neutral and oil stay on most of the time, all other marker, signal and driving lights alternate. I pulled the ignition switch, cleaned the contact points, greased the turn mechanism, soldered a wire back into place, put a new body and earth ground on. Presto, no improvement.
This should be a fun one.
There are probably hidden relays and switches within the harness.
1st step--identify exactly which lights or devices cut out.
You'll have to trace the positive wire of that dead light back through the harness to see where it goes.
That one light may lead to your entire issue..