Forum Discussion

CobraGT40's avatar
CobraGT40
Explorer
Aug 23, 2013

Trailer Wiring Conundrum...

Hi all
I'm not really sure where I should post this, but here goes.
I have a '98 Jayco Eagle 293-RKS that I tow with my 2000 Ford F-250. I had some right turn signal/right brake light issues when I hooked up to return from Wisconsin earlier this month. I figured it was an issue with the trailers themselves ( I tow a small 5x8 trailer behind my 5th wheel ).

Anyways, I decided to change out the lights on the small trailer with LEDs... same issue. Turns out that the issue is with the wiring harness on my TRUCK, not the trailers.

So, I picked up a Hopkins wiring kit (#40955), figured I'd just replace the one I have since the spring-loaded weather cover was broken. It says it's an "Exact OEM Fit". However, it does not work on my truck. After a bit of poking around online I found that Ford had 2 different factory wiring harnesses. One for 4 blade and a different one for 7 blade. My truck didn't come with a 7 blade (it was added by the guys that installed my 5th wheel hitch, brakes, etc.)

Anyways, I was hoping that there is an adapter so that I can use my new Hopkins kit (it has both 4 blade AND 7 blade...which I need since I pull a small trailer behind my 5th wheel as well)

Does anyone know if there is an adapter kit for this ...or another solution ? I truly loathe messing with any wiring... any ideas ?

Thanks !

Scott
  • Dave_H_M's avatar
    Dave_H_M
    Explorer II
    Sep 10, 2013
    I decided to put 7 pin RV plug on the flat bed.

    now I am all on the same sheet of music.
  • whiskyrunner's avatar
    whiskyrunner
    Explorer
    Sep 10, 2013
    Why can't they just make a figgin adapter ! lol

    They do make one, I use a flat 4 in my round 7 all the time
  • CobraGT40's avatar
    CobraGT40
    Explorer
    Sep 09, 2013
    sdetweil wrote:
    here is a very helpful, straightforward wiring diagram with colors for trailer hookup

    etrailer wiring help

    see the bottom of the page for colors by vehicle manufacturer (to find your Orange wire)


    For some reason, my factory wiring is a bit different than the one in this link... But at least I know what the thin Black wire on the Truck side is, I'll hook that up to the Purple on the pigtail side. And the Orange on the truck side to the Black on the pigtail side...
    WHEW !

    I'm going out to move my trailer this afternoon, so I'll let y'all know how it worked...

    Thanks ! ! !

    Scott
  • sdetweil's avatar
    sdetweil
    Explorer
    Sep 09, 2013
    here is a very helpful, straightforward wiring diagram with colors for trailer hookup

    etrailer wiring help

    see the bottom of the page for colors by vehicle manufacturer (to find your Orange wire)
  • CobraGT40's avatar
    CobraGT40
    Explorer
    Sep 09, 2013
    OK...

    Here's where I started on the battle of the wiring...

    I have all the wires on both ends (truck side and pigtail side) connected to their matching colors (as I did all along). But there were the two colors left over, one on each side of the connection. Left over were Purple (pigtail side) and Orange (truck side). I know Purple on the pigtail side is for back up lights (which aren't used) and the Orange on the truck side is the 12v.





    Here's where I am now... Upon a second look (more like 5th or 6th look), I noticed that the Black wire on the pigtail side is thicker gauge than the Black wire on the truck side... I have these two wires connected. I noticed that the gauge of the Black wire on the pigtail side is the same gauge as the Orange wire on the truck side...



    Follow me so far ?



    Is the Black wire on the pigtail side the 12v connection ? And if so, what the hell is the thinner gauge Black wire on the truck side ?



    Why can't they just make a figgin adapter ! lol



    Thanks !



    Scott
  • sdetweil's avatar
    sdetweil
    Explorer
    Aug 26, 2013
    CobraGT40 wrote:
    OK

    After looking into a bunch of options, I decided that my best solution will be to splice the factory pigtail to the new receptacle...which is essentially what the RV shop did originally.

    I'll solder the connctions and apply heat shrink tubing to keep the moisture out. (which is why the RV shop patch job failed)

    Looks to be fairly straight forward ... but my only question is: There is an ORANGE wire on the factory pigtail side. There is no orange wire on the 7 blade side.

    Does anyone know what the orange wire is ?

    Thanks !

    Scott

    see etrailer wiring help
    'Wire Color by Vehicle Manufacturer'
  • CobraGT40's avatar
    CobraGT40
    Explorer
    Aug 26, 2013
    OK

    After looking into a bunch of options, I decided that my best solution will be to splice the factory pigtail to the new receptacle...which is essentially what the RV shop did originally.

    I'll solder the connctions and apply heat shrink tubing to keep the moisture out. (which is why the RV shop patch job failed)



    Looks to be fairly straight forward ... but my only question is: There is an ORANGE wire on the factory pigtail side. There is no orange wire on the 7 blade side.



    Does anyone know what the orange wire is ?



    Thanks !



    Scott
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Aug 23, 2013
    "My truck didn't come with a 7 blade (it was added by the guys that installed my 5th wheel hitch, brakes, etc.)"

    " I truly loathe messing with any wiring... any ideas?"


    Take it back to the guys that did the 7 pin wiring and have them install your new 4 pin and 7 pin kit

    Otherwise....remove the 7 pin receptacle on truck and wire up your 4 pin and 7 pin plugs.
    All necessary wring is right there.

    Here is a great trailer wiring site....pictures/diagrams/charts etc.
    LINK

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