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benjicunney's avatar
benjicunney
Explorer
Jul 29, 2016

SOLVED! Trailer pigtail issue

I just bought a new 2016 F-150 that I'm using to pull my trailer. My parents were using it during my purchase and have recently returned it. When I hooked up my trailer the right turn signal doesn't seem to be working. I get a fault code on my screen indicating the right marker isn't working.

However, when my father hooks it up to his older chevy the right blinker works just fine. We've tested that the right turn pin on the female receiver of the truck is getting power. And we've hooked my truck up to a different trailer and the right hand turn signal worked. The pigtail fits a bit loosely in the receiver so wondered if that might be the problem.

Lastly, the right hand light was a replaced light a year or so ago because its a light that also has the license plate holder and that broke. We made sure the bulb are the same. But maybe the fixture itself pulls a different amperage and is throwing the fault code?

Any thoughts? I'm baffled that it works for my father's truck but not mine, and that my truck worked on a different trailer.
  • Solved the issue. It was a bad ground connection back at the light. Removed all wire connectors and found that one wasn't making a good connection with the ground wire. My F-150's computer was sensing the issuing and throwing a fault message and stopped sending power. My Father's older Chevy doesn't have the fancy computer so was just sending power. Both lights are of the same brightness now as well.
  • Shadow Catcher wrote:
    I found out today that wiring can be a difference between RV and utility trailer wiring.



    I think you will find it is only the wire colors.
  • I found out today that wiring can be a difference between RV and utility trailer wiring.

  • Check your Ford manual you may have a fuses for the trailer wiring. My 1999 F550 does.
  • benjicunney wrote:
    Lastly, the right hand light was a replaced light a year or so ago because its a light that also has the license plate holder and that broke. We made sure the bulb are the same. But maybe the fixture itself pulls a different amperage and is throwing the fault code?

    Any thoughts? I'm baffled that it works for my father's truck but not mine, and that my truck worked on a different trailer.


    Any chance the original bulb was incandescent but the replacement is LED? Some vehicle electrical systems don't deal well with LED bulbs.
  • RoyB's avatar
    RoyB
    Explorer II
    I carry one of the 7-way Trailer Connector testers - Got mine from ETRAILER but I have seen them in some auto parts places...




    When you plug this into your truck trailer socket then it only see's the truck side. If the small LED lights work normal then there is not problem with your truck side...

    Also on my 2010 new F150 Truck I had to install a RELAY and a FUSE that was in a unmarked plastic bag. This has to do with the TRAILER CHARGE DC voltages coming from the truck. It is only present when the truck ignition Key is turned ON. I found this bag in the truck glove box with no info with it. You can see where it plugs in by looking in your manual marked TRAILER CHARGE...

    Trailer grounds and sometimes shorted out bulbs cause weird problems...

    By eliminating the truck side being the problem it helps speed up tracking the down the problem on the trailer side...

    ETRAILER.com has good info on its site to help you along...

    Roy Ken