Forum Discussion

motorboatinking's avatar
motorboatinking
Explorer
Mar 04, 2015

Wire harness adapter help

I just bought a 1996 Jayco Eagle 8 popup camper. It has a 7 way plug. The owner before me did not have a vehicle with a 7 way harness, so he installed additional brake lights to the trailer, that are on their own 4 way harness. So, the trailer has a 4 way and 7 way harness. I drive a 2013 Outback, and only have a 4 way harness. I want to use the 7 way harness though, because I don't like the lights that the 4 way harness is wired to. I don't know if the trailer has brakes, or if they would be surge or electric brakes. The trailer is so light that even if it did, I probably wouldn't get a brake controller. I just want to use the original lights, and have the fridge powered while the vehicle is running. What kind of adapter would be best for my situation? Thank you.




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7 Replies

  • handye9's avatar
    handye9
    Explorer II
    Mar 04, 2015
    motorboatinking wrote:
    Oh I don't know why I didn't see that. What about this one. I would just tape up the other wires, and if I wanted to i could route the hot wire to the battery and have a hot wire.



    That looks like the right gender.
  • motorboatinking's avatar
    motorboatinking
    Explorer
    Mar 04, 2015
    Oh I don't know why I didn't see that. What about this one. I would just tape up the other wires, and if I wanted to i could route the hot wire to the battery and have a hot wire.

  • handye9's avatar
    handye9
    Explorer II
    Mar 04, 2015
    Those adapters won't work, because they are the same gender as the plug on the trailer. The trailer won't plug into the adapter on the seven way end, and the car won't match up to the 4 way end.

    Only way I can think of to hook a 4 way into the trailer's original wiring, would be to cut (or disconnect) the 7 way plug and wire a 4 way (trailer end) to the corresponding wires. That won't give you a power wire for the fridge or brakes, but, it would run the lights.

    Requirement for brakes is based on trailer weight. That trailer doesn't appear to be heavy enough to need brakes.
  • motorboatinking's avatar
    motorboatinking
    Explorer
    Mar 04, 2015
    Would something like this work for just the lights? I can except that there won't be a hot wire for the fridge. But this will just make the lights work correct?

  • enblethen's avatar
    enblethen
    Nomad
    Mar 04, 2015
    Remove the added lights and wiring harness.
    Wire a four way connector on the trailers factory wiring corresponding to your Outback connector.
    Problem That I see is there will be no charge circuit from the Outback. Note the black wire in the seven wire setup.
  • motorboatinking's avatar
    motorboatinking
    Explorer
    Mar 04, 2015
    I looked under it and it looks like the wheels are just on an axle, so I'm almost positive there are no brakes. I can look up adding brakes, but how hard would that be?
  • ScottG's avatar
    ScottG
    Nomad
    Mar 04, 2015
    Well I can see it doesn't have surge brakes. You should be able to look at the back side of the wheel hubs and see if wires are coming out to tell if it has electric brakes.
    If it does then you need to get a brake controller and install a 7 way connector. An adapter isn't going to work as you missing a charge wire and a brake activation wire. You need to add those.
    FWIW, If it has brakes then I would use them and if it doesn't then I would add them. Given the size of your tow vehicle, it will make a huge difference in a panic stop.

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