wire harress

Discussion in 'Trucks and Trailers' started by exmark72, Oct 29, 2006.

  1. exmark72

    exmark72 LawnSite Member
    Messages: 123

    on my truck now i have the 4prong harress but i need i 7 prong haress to tow a different trailer. what would need for the 7prong setup?? and where possible could i get it??
  2. FearThisDeere

    FearThisDeere LawnSite Bronze Member
    Messages: 1,154

    If you are not towing a trailer with brakes, the make an adaptor that will bring you from a 4 flat to a 7 round for about $20. If you are towing a trailer with brakes you will have to get a different harness from the front of the truck all the way back (I think) and then wire it all into a brake controller. When I went from a 4 to a 7 it was around $270 with the cost od the brake controller I think.
  3. exmark72

    exmark72 LawnSite Member
    Messages: 123

    no it will have brakes soon
  4. DBL

    DBL LawnSite Silver Member
    Messages: 2,219

    pep boys has all types of adapters just plug and go cheap too
  5. exmark72

    exmark72 LawnSite Member
    Messages: 123

    dont need a damn adaptor i need to know what i need to get so i can hook a trailer with 7prong plug to my truck.. the trailer has brakes which i will eventually use.
  6. FearThisDeere

    FearThisDeere LawnSite Bronze Member
    Messages: 1,154

    This is what you'll need^^^^.
    Brake controller, brake controller wiring harness for the make of your truck, 7 round plug for the back of the truck, new wiring all along the truck, etc... I thik I've listed everything. Someone else might be able to do better than me.
  7. Total.Lawn.Care

    Total.Lawn.Care LawnSite Senior Member
    Messages: 840

    You need to get the following, and it can all be obtained from a decent Auto Parts store, Walmart or your nearest RV Dealership.

    Brake Controller ($69-$140)
    7-Pin Harness for Truck ($25)
    50' Roll of Blue 12 ga. Copper Wire ($10)
    50' Roll of Red 12 ga. Copper Wire ($10)
    50' Roll of Black 12 ga. Copper Wire (10$)

    The Seven Pin Plugs have the following connections.
    Running Lights - Brown Wire
    Left Turn - Yellow Wire
    Right Turn - Green Wire
    Ground - White Wire
    The above are in the 4 Pin Fat as well.
    Orange - Auxillary
    Blue - Trailer Brakes
    Black - 12V Power Lead.

    Wire up the existing four wires into the seven pin plug using the color coded reference that comes with the plug.

    Use the Red, Black and Blue wire to make an additional wire harness to run the trailer brake lead ( on the blue wire) from inside the cab tot he 7-Pin plug, same with the Black for a 12V+ Power lead. The Auxillary is sometimes used for Backup Lights. You may opt not to run this wire at all.

    This process creates you a functional 7-Pin plug so that you can run brakes.

    It you need dditional help or have questions, PM me, I have done this a few times.

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