Rear brake lite works, but not running light.

[mfarrington]

My 79 XS11 tail light suddenly desided to crap out. Brake light works fine. New bulb didn't fix. Can anyone help this non-mechanic identify the wire I need to trace down? Any help is appreciated!

[TopCatGr58]

Hey Farrington,

IT's the blue wire in the harness going to the rear light assembly. Take off the seat, sometimes the wires get caught between seat and fender, chaffed, cut, pulled loose, etc.! Also, even before that, check your FUSES!!! The brake lights are on a different circuit than the tail/dash lights! Do your gauge lights still work??

If not, then it's most likely the fuse. IF you are still using the glass fuses, you need to actually PULL it out, check the brass clips, they can corrode, crack, loose their tension, along with the fuses themselves can go bad but still look good, check with a ohmeter!
T.C.

[John]

The blue wire is the one you need to check. Do the gauge lights work?

[mfarrington]

Thanks to both for your speedy replies. Yes, my gauge lights do work. I'll check the blue wire.

And funny thing you should mention "the fuses themselves can go bad but still look good" . . . ...

Regards to both,