CB77 Brake Light Issue

[Merz64cb77]

For some odd reason my brake light stopped working out of the blue however, the running/parking light portion still works. Thus far I ve checked the bulb, stop switch voltage and blue/white wire continuity and all check out? Any ideas on what I could look for or what the issue could be. The peanut bulb in the headlight also works fine.

Thanks

[DJM]

It could be the contacts inside the actual bulb holder, I've seen them described as 'snake's heads' presumably because of their shape.

They tend to soften and don't always make good contact with the bulb.

Remove the bulb and pull them both gently backwards using thin nose pliers or tweezers.

While you're in there it's a good opportunity to check with a voltmeter to see if you have 12 volts there when the rear brake is applied.

There should be a constant 12 volts on one contact when the pilot / running light is switched on with 12 volts on the other contact when the brake is applied.

If you don't have this then the problem lies elsewhere, if the brake light switch is good are you sure it is adjusted correctly?

[Merz64cb77]

Thanks for the reply DJM I really appreciate it.

I checked the contacts to ensure they made good contact with the bulb. They were ok but I pulled them a tiny bit just to be sure.

I thought it might be a ground issue so I jumpered a wire to a good ground on the frame and to the light socket but no light so it was not a grounding issue.

I also checked the volts with the multimeter and had 12V but only for the parking light.

I then disconnected the two wires at the switch and checked for continuity across the switch wires and at first had an open circuit but then pulled the rubber dust cap off the switch itself and found the issue. The blue wire looked a little worn and had pulled away from the switch. I cleaned it up and put a drop of solder on it, re connected the wires to the harness, pressed the brake and had light.

Thanks again for help and troubleshooting ideas.