Brake light works but running tail light does not work.

[EvanNaculum]

After market taillight. Was working fine for weeks, then out of the blue it stopped working. If I hit the brakes, front or rear it lights up. So the bulb is fine. All three connections are solid, black with white stripe, white with black stripe and gray. What's the trouble here?

[Noble]

Why do you think the bulb is fine? It is LED or standard 1157 bulb? If it is a bulb, replace it. There are 2 filaments in the bulb. Probably 1 is burned out or a bad connection between the socket and the bulb.

[Craigo]

+1...If you have a good look at the bulb (if a bulb type) you will most likely find that the tail light filament is broken.....

[EvanNaculum]

Why do you think the bulb is fine? It is LED or standard 1157 bulb? If it is a bulb, replace it. There are 2 filaments in the bulb. Probably 1 is burned out or a bad connection between the socket and the bulb.

+1...If you have a good look at the bulb (if a bulb type) you will most likely find that the tail light filament is broken.....

I'll take a look at it...figured the bulb was fine since the brake light works, there's 2 different bulbs in there? Guess that makes sense since the brake light is brighter than the running light

[EvanNaculum]

Lol

Your right, filament is broken. Thanks guys!

[cryptomail]

Hey guys, same problem....and guess what EvanNaculum and I had the same problem and solution as well!

One of my filaments was simply, dusted! ?

 

Just wanted to say thanks to all of you who pointed out there's two filaments in that 1157.

Really appreciate it, and while it's an "A-DOI DERR" moment for me, I'm pretty solid in understanding now that there's two filaments in there ?

[michaelks]

My rear light was stuck in brake mode. I removed the right hand cover to do the loctite fixes and had to also remove the brake pedal, and doing that I must have knocked the brake switch out of place. It's held by a rather fragile fixture.

[38super]

Just a heads up, some of the aftermarket Baja / Dual Sport lighting kits have very cheap light sockets.  Poor spring tension will cause intermittent operation.  Of course the only person to notice is the local constabulary.