Forum Discussion

josheaton's avatar
josheaton
Explorer
Mar 31, 2017

Help! 4way to 7 way Converter

I'm trying to convert my 4 way trailer connection to a 7 way connection. I ordered this kit.

https://www.etrailer.com/p-37185.html

I do not have a red wire in my harness for the trailer battery. What am I missing? I'm supposed to have this thing hooked up in the morning and I'm at my wits end. Please see pictures below.



18 Replies

  • Thank you, this helps. Although from my pictures, it appears that I don't have this black wire which I assume will need to be run from the battery. Bummer...

    RSD559 wrote:
    I believe, on my F150, the black wire was the one for the trailer battery feed, and blue one was for the brakes. The tag on the harness says it's a Ford.
    http://www.f150-forums.com/attachments/1997-2003-ford-f150-7/48d1303303854-trailer-wiring-excursion-related-ugg-7waytrailerend-jpg
    is a link to a picture of the correct colors to function. Good luck!
  • Sorry all, yes it is a 2016 F-150. So from what I've read here, does this mean that there is no 12 volt DC line at that connection and that I have to run it all the way from the battery?

    The truck is. a 2WD F150 with the 5.0 V8. It did not come with the towing package (got an amazing deal on it) and am trying to retrofit the towing components. Had a transmission cooler installed, and this is really the last thing I need done.

    The camper we're purchasing this afternoon weights about 3500 pounds dry and fully loaded will be about 4500. Tongue weight is 375.
  • The link the OP provided has directions for installation and it directs him, in part, to run the black wire to his battery with a fuse.
  • RoyB's avatar
    RoyB
    Explorer II
    Usually speaking if the tow vehicle only has a 4-way type connection is wasn't a big enough truck to tow a very large trailer - maybe something like the small utility trailers... These same tow vehicles also usually only have the one-inch size trailer hitch setup as well

    I always got all of my trailer wiring info from the ETRAILER.com site. Guess they still have all of that info available along with lots of how to videos...

    My two most recent FORD trucks had the 4-way/7-way Combo Trailer connector installed... Pretty neat having both connectors to use..

    If I was changing a 4-way over to a 7-way I would install this combo connector setup...


    Moderator notified to resize the very large photo from the OP here... Sure creates a big mess trying to view and make comments when one that large is being used. Most of my general info photos use the 300 setting and then I like to use the 400 setting for large view of something. I think the max the RV NET management likes to see is the 600 size... It was like moving my screen over to the next county here to get to the links to make comments hehe...

    Roy Ken
  • I believe, on my F150, the black wire was the one for the trailer battery feed, and blue one was for the brakes. The tag on the harness says it's a Ford.
    http://www.f150-forums.com/attachments/1997-2003-ford-f150-7/48d1303303854-trailer-wiring-excursion-related-ugg-7waytrailerend-jpg
    is a link to a picture of the correct colors to function. Good luck!
  • Pull wire from the truck battery. Best to include 40 amp fuse near the battery.
    Trailer battery should get you to camp fine without the trickle charge. If your destination has electric you could just skip it and roll. Plug in while you pack to top it off.
  • I agree with my esteemed colleague with the exception of the relay. I've done it both ways and prefer to run with it connected to the TV battery all the time. Either way, it will work fine.
    I would install a 40 or 50 amp auto-resetting breaker too.
  • It would be nice if you told us what brand of truck you are working on.

    So if you don't have the red battery wire you will need to add it. I would use a 10 gauge wire from your truck battery threw a relay that will only provied power when the truck is running. Then back to your new trailer plug.