brake light not working

[benshannon]

Hey guys,

thanks for the replies to my newbie post. Anyway, i was giving the bike a run this morning
which was great, sounds gorgeous. I checked all of the lights,
all lights work, apart from the brake light. If i squeeze the front brake or press the rear brake
the rear light doesn't come on, but it does work as a rear light. I hope that makes sense.

What should i check to fix the brake light? I guess its a cable issue?

thanks

Ben

[MarkB]

I had a similar issue with my 1976 Sport: I could choose between the brake light working or having the rear light on, but not both at the same time. A good clean of the earth connection on the rear mudguard fixed the problem.

[mad muller]

I would check the bulb to see if its working , easy job and cheap to purchase from local car spares shop .

[benshannon]

The bulb works fine as the light comes on when i turn the lights on but it doesn't come on or get brighter when i apply the brakes
i shall have a go at cleaning the earth connection. Is there a fuse or anything?

[Monstyr]

It ought to be a dual filament bulb, its possible that one of the filaments has blown , take it out and have a close look at it to check.

[EVguru]

Depending on year you may well not have a front brake light switch.

The rear switch was originally on a bracket, but many are not functioning 30 years on and there is an alternative replacement cable available with an inline switch. Those switches don't seem to last all that well.

First find your switch (or switches) and try pulling off the connections and connecting them together. If the brake light comes on, then the switch was at fault. If not you're going to have to trace the wiring and check all the connections.

[corsaro chris]

To add to Pauls comments;

Two types of rear light lens;

Early ones have a twin filament bulb; it's quiet common for one of these to burn out, so you either have a tail light or a brake light. Unscrew the red plastic cover and take the bulb out to check if both filaments are unbroken.

Later (non-original!) lens have two separate bulbs, and again check the filaments to see if they are unbroken. I had one of these on the Sport, but all bulbs were fine. I checked the brake switch (only on the rear brake on the early Sport) and restored electrical connectivity through cleaning and a good water dispersant spray; which, from memory, I don't think Paul approves of!

You can check for connectivity through the wiring by connecting those that feed the brake switch briefly together with the ignition on - if this lights the non-working bulb you know it's the switch. New switches are cheap and easy to fit if this is the problem.

Good riding,

CC