cb77 lighting wiring

[GregMcN]

Just wiring up my US spec cb77 and can not fathom the rear light at the moment.
The wiring diagram I have is for a bike with a pilot light and there is essentially a white wire that runs from the rear light to the headlamp shell. My bike has no pilot lamp, a one position lighting switch. It has a white wire at the rear light which links to the main ignition switch but no white wire at headlamp shell so I can not work out what feeds the rear light. The headlamp is working OK but no rear light.

Thanks Greg

[GregMcN]

Problem solved I think. Looking again the feed for the rear light is green wire return from the headlamp shell which goes to the main switch which connects with the white rear light wire when the ignition is on. The reason it is not working is that there is no earthing at the rear light due to new paint. Frustrating to have to remove new paint on the rear light bracket to make the earth but that is what I will have to do. I did look to see if I could run a wire instead but no room for a hidden wire.

Greg

[leonvjames]

I rubber mounted the tail light assembly on my CB77 to try and increase the life of the bulbs. Less vibrations. To provide an earth return I made up a jumper from flexible wire and connected it between one of the tail light mounting bolts and one of the mud flap at the back of the mudguard. This was inside the mudguard.

[DJM]

On my CB77 resto I actually ran three wires inside a sleeve all the way from the rear light through to the frame. As you can't really see any of it I wasn't too bothered about originality.
I connected the ground wire direct onto the bulb holder plate in the light unit, at the front end I connected it onto the frame or perhaps even onto the battery.

In my experience, with restored bikes 'additional' earth wires are always worth the effort, powder coating doesn't pass current too well.

For the rear light to work well the current has to pass from the bulb-holder plate to the light bracket, then to the rear fender and then to the frame, all of which will probably be powder coated. I'd run an extra earth wire every time!