Forum Discussion

engiman's avatar
engiman
Explorer
Aug 01, 2020

Running lights staying on

I have a 38 ft trail runner. It is parked at a trailer site. All of a sudden last week I noticed my outside lights on the trailer are staying on. They have never come on because we don't tow it. Any help would be appreciated.
  • Outside being?
    Running lights
    Tail lights
    porch light

    Porch or rope lights could be as simple as someone bumped the switch, running/tail with no vehicle could be something making a connection at your 7 pin plug powering them from the trailer battery. Clean/clear the plug and recheck.
  • Yes its the tail lights and running lights. So this plug is at the front of the trauler I presume . Would that be the plug that you use to tow. Sorry am still new at this.
  • You may have a fault in the trailer plug or elsewhere. If the running wire comes in contact with the 12 volt wire the lights will come on.
  • I had an Award TT that all of a sudden started doing that. I noticed after a while it was doing it in the middle of the day when it warmed up, they would turn off when it cooled down in the evening. I narrowed it down to one of the running light wires in the ceiling was shorted to one of the ceiling light + wires (I`m assuming pinched somewhere). when I removed the fuse for the ceiling lights the running lights would also go out. I just cut the power feed to the ceiling lights and ran a new wire for them. That was the easiest fix short of removing the entire ceiling and trying to locate the short!
  • On a trailer my dad had the running lights came on with lights in a storage area.
  • I agree with the earlier comments, check the 7-way plug. If the 7 way has a plastic cover for when not in use, make sure it is not trapping water, that will complete the circuit and your running lights will come on.
  • Danoo wrote:
    I agree with the earlier comments, check the 7-way plug. If the 7 way has a plastic cover for when not in use, make sure it is not trapping water, that will complete the circuit and your running lights will come on.


    Toss the entire plug in water, ain’t nothing gonna happen.
  • If it is a factory plug it should be fine, but if an aftermarket one, that has a couple of screws holding the fat end of the plug together then do take it apart and see if any little wire strands have escaped and visiting the neighboring wires. It is only the 12V positive wire that can make the lights come on. It is possible to pull wires that are otherwise fine out of place when taking the plug apart, so beware you could double the problem if not careful.

    Otherwise, as mentioned, you likely have a short within the bowels of the camper. To run new wire from where the trailer/truck plug is wired to the camper (near a fuse box) and all the way to the light... to every single light around the camper will be a big job. Hopefully the short is either in the plug head or right there at the fuse box area.
    First check the tail light bulbs and wiring, a short here is easier to fix. Look behind the fixture that holds the bulb to see if its wire is shorted.