[entukay]

OK, i have a cb350 twin 71' and it seems as if the rear brake light is always on. I have checked the switch that for the rear brake pedal, and even when i totally take it off it doesnt solve the problem. I am not sure how to check the front brake light switch. What else could the problem be?

 

[Ease]

Have you tested the 3 wires for ground, aux power and constant power?
Sounds like the constant power wire is wired up to the auxilary (brake light) wire on the taillight.
Either that or the brake light switch is stuck on.

Hey By'

 

[entukay]

Im not sure where those wires are or how to test them, could you elaborate a bit further please? thanks!

 

[Ease]

There are 3 wires coming out of your taillight.
One of them is a ground wire, one is constant power, and the other is your brake light power.

Assuming you don't have a meter, the best way to test is simply to turn your key on.
If the light is dim (one filament) and you press your brake, it should get twice as bright (2 filamints light up). If it doesn't get brighter (or just gets a LITTLE brighter) then switch the 2 Live wires.

Are you installing a new taillight? Or is this the stock / unaltered harness?

Hey By'

 

[entukay]

actually i realized it's not staying on, its just not working at all, the tail light works when i have the lights on, but doesnt get brighter when i hit the brakes, and if i dont have the lights on it still wont come on at all.

I dont think the wires are crossed as it was just working a couple days ago, the bike is all stock, and i've never messed with anything.

 

[Ease]

Hmm...
Well then I'd lean toward the brake switches beiong stuck / dirty / shot.
I've never had mine apart, so I wouldn't know how to run you through it.
Check your manual on how to clean up your switches.

Hey By'

 

[peteN]

brake light switch stuck on? see this a lot especially during inspections; usually the rear switch is adjusted out too far because it got adjusted or installed incorrectly, or the rear brake isn't adjusted right, etc. try lifting the plunger of the switch away from the brake pedal hook that it's on. if this temporarily solves your problem, adjust the switch closer to the pedal using the threaded nut that it sits in. this should shut off the brake light and leave your tail light working all by itself.

if at first you don't succeed, use a bigger hammer

 

[kenessex]

Check the bulb

Ken

AHRMA 412
Vintage racing - old guys on old bikes