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WAM's avatar
WAM
Explorer
Jul 09, 2014

camper tail lites

Probably shorted trailer wiring took out both the trailer tail lights and the camper tail lights. I found and removed an exposed wire.

But I can't get the tail lights back. The tail lights on the truck are working, but not on the camper or trailer. I found a fuse in the camper labeled running lights but it seems intact. I changed it anyway with no effect.

I wonder if the truck feeds the trailer circuit from a different source than the regular truck tail light wiring? It's a 2013 F350 SD.

I'm thinking maybe the camper tail lights get power from the truck trailer wiring instead of the truck tail light wiring. That might explain why the truck lites work and the camper's don't. Anyone know?
  • Probably not, but wouldn't have hurt to try. Wasn't a fixed short but an occasional intermittent. Even before I found the bad wire it passed the VOM resistance test.
  • WAM wrote:
    Yeah, I can confirm now that it was an underhood trailer running lights relay fuse. (not a relay -- fuse to a relay)

    On a late F350 it's in space #26, it's 30amps (pink)and is a shape I was unfamiliar with. Basically a 1/2" cube with a translucent lid so you can see the traces between a pair of solder dots. The local autoparts store had it. This one is called low profile as there is a similar one 50% longer. No idea why.

    Now I just hope the damaged section of wire I replaced is the only fault.


    You can check the wire with an ohm meter before plugging into the truck wiring.
  • Yeah, I can confirm now that it was an underhood trailer running lights relay fuse. (not a relay -- fuse to a relay)

    On a late F350 it's in space #26, it's 30amps (pink)and is a shape I was unfamiliar with. Basically a 1/2" cube with a translucent lid so you can see the traces between a pair of solder dots. The local autoparts store had it. This one is called low profile as there is a similar one 50% longer. No idea why.

    Now I just hope the damaged section of wire I replaced is the only fault.
  • The Dodge even has L and R fuses under the hood...more fuses...I keep a packet of all types in the camper at all times...it has come in handy...neede one for water pump yesterday. Go Figure!
  • Yeah I think I'm making progress. The trailer takes power from a separate family of "trailer fuses". The camper draws it's power from that same trailer wiring.

    So if the trailer blows a trailer tail-light fuse, both the trailer and camper will lose the lights. But not the truck. I think I found the bad fuse, but it's a weird shape and I have no spares. Off to the auto parts store.
  • The lights will get power from the truck. Are any lights including running lights working? You probably should also check the truck fuses.