Forum Discussion

dgrimes80's avatar
dgrimes80
Explorer
Aug 24, 2017

Taillight issues

I am having an issue on my travel trailer where the brake lights work but if I use the turning signal or emergency flashers it pops the fuse on my truck for the LH light and the RH light doesn't flash but doesn't pop the fuse. First, I have no idea what is causing it, but I know that it is isolated to the camper because I have a small trailer and the flashers work without blowing fuses. So I decided to look at the wiring under the camper and nothing looks out of place but it doesn't mean that it is perfect because I can't see all of it. So I decided to replace the tail lights because I have wanted to put LED lights on it but also because I figured I could rule them out as the issue. The problem is they put about a half a tube of caulk in the hole where the wire goes through the exterior. Also, I don't know if I can even get to where the tail lights connect to replace them. Has anyone done anything like this? Do I need to take the interior wall off to access these wires? I am trying to avoid taking it to the dealer, but I am running out of patience with it.

9 Replies

  • Hornnumb2's avatar
    Hornnumb2
    Explorer
    Aug 25, 2017
    I think I would take the taillight out of the equation first instead of just removing the bulb. Then you can move to the junction box.
  • dgrimes80's avatar
    dgrimes80
    Explorer
    Aug 25, 2017
    rjniles wrote:
    Remove the bulbs and operate the signals. If the fuse blows you know it is the wiring.



    Ok I just tried this and it still blew the fuse. The 7 way cable that plugs into the truck goes into a junction box under the camper. I'm think I should cut the wire there and hook it up to see if blows. That would rule out the 7 way. The reconnect to see if it is just an issue with the connection there and see if it blows. Then if it does that would tell me the issue lies in the wire running from the box back to the lights. Am I thinking right with this?
  • jkwilson's avatar
    jkwilson
    Explorer III
    Aug 25, 2017
    I replaced the bulbs and it popped the fuse when I turn the turning signal on. Should I assume at this point that I need to run new wires for the tail lights?


    rjniles wrote:
    Remove the bulbs and operate the signals. If the fuse blows you know it is the wiring.


    Do this ^ first
  • westend's avatar
    westend
    Explorer
    Aug 25, 2017
    dgrimes80 wrote:
    Thanks everyone for the help. I replaced the bulbs and it popped the fuse when I turn the turning signal on. Should I assume at this point that I need to run new wires for the tail lights?
    That would probably be the best solution because you'll know that you have good wire and good connections to the lights.

    Tracing a wiring fault to the back of a travel trailer can be a hair-pulling event. There are a lot of places where a short can develop or a wire is nearly parted within the jacket, unviewable by visual inspection.

    FWIW, when I restored my trailer and replaced all the wiring, I soldered and heat-shrinked any splices. I engineered in one spot that has the 4 wires exposed inside the trailer, aft. If I have a wire issue, I'll at least be able to partly trace the fault. If I was blowing fuses, the only solution would be replacement and I would pull wire through either a hose remnant or flex conduit, fastened to the underside of the trailer.

    Good luck with your light issue.
  • dgrimes80's avatar
    dgrimes80
    Explorer
    Aug 25, 2017
    Thanks everyone for the help. I replaced the bulbs and it popped the fuse when I turn the turning signal on. Should I assume at this point that I need to run new wires for the tail lights?
  • rjniles's avatar
    rjniles
    Explorer
    Aug 24, 2017
    Remove the bulbs and operate the signals. If the fuse blows you know it is the wiring.
  • Bob_E_'s avatar
    Bob_E_
    Explorer
    Aug 24, 2017
    I'm currently dismantling a camper to rebuild it. And when I pulled the lights off, the wires from the lights are about 6" long and were connected to the main trailer wiring just inside the aluminum siding with wire nuts. They were all easy to access. Obviously, I can't guarantee it, but I'd suspect yours would be similar once you pulled the caulking out of the hole to access the wires.
  • bguy's avatar
    bguy
    Explorer
    Aug 24, 2017
    Inspect the bulbs. I've seen filaments shorted in dual filament bulbs. I've also seen bulbs shorted in the socket.

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