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Wiring a trailer doesn’t have to mean splicing or chasing down factory wires. The Curt T-Connector plugs directly into your vehicle’s existing harness behind the rear bumper to create a clean 4-flat trailer connector. It’s a straightforward plug-and-play setup that gets you towing lights in minutes without any guesswork.
Once installed, the 4-flat connector gives you what most trailers need—running lights, brake lights, and turn signals. It’s the standard plug used for small and midsize trailers, and it connects easily to most wiring adapters and accessories.
Starting with a solid 4-way makes it simple to upgrade later. If you decide to add trailer brakes or a 12V charge line, just plug in a 4-to-7 adapter like part #37185 or use an install kit such as #ETBC7. The C56031 provides the base connection needed for either setup, so you can build on it when your towing needs grow.
If you’re adding an LED tailgate light bar or other rear lighting, this harness gives you an easy power source without cutting into the factory wiring. The 4-flat plug provides clean, reliable signal connections that keep your setup looking tidy and professional.
Customer Satisfaction Score:
88% were satisfied with this product
12% of customers were not satisfied
Ratings & Reviews
Exactly what my local parts store couldn't provide me. Going fishing.
quality product. Took less than 10 minutes to install including wire ties. Product was shipped fast and was well packaged. Will purchase from e trailer again
Everything worked to perfection. Plug and go is the only way to get connected.
Great website ! Greatly appreciated watching the how to videos.
Great product best harness I’ve ever had
Plug and play. Easy. I like easy...rather than splicing wiring, as the local shops all wanted me to do. Excellent.
Quick shipping and great customer servi ce!
This item works great for my 1998 F-150! I now have trailer wiring.
Quality product perfectly fit my truck and works great. Best customer service I've experienced from any place of business ever.
Product was delivered as advertised fit perfectly came in good condition and the shipping was great will do business again with you
Andy gave me some incredible customer service and I'm so happy I went with etrailer for my wiring harness.
T-Connector wiring harness fit perfect. It came exactly as described and earlier than expected! You won't be disappointed!
Great part...Just what I needed to get this truck and trailer together...

Glenn C.
4/13/2017
Still As Good As New
Product work just like it should, delivery was quick. Will order again from etrailer. Would recommend anyone needing parts for your trailer wiring to use them.
Fit perfect. Directions spot on.
It worked. I thought I was getting a harness that plugs into the main harness that y's off from the plug in the frame. Lucky for me the tail light side of the old harness still worked because all this does is plug into that. I could of done what this plug does for free and a little bit of solder.
Plugged it in and in 5 minutes had trailer lights. Could not find the correct harness at any auto parts stores. Will definitely be back for any needs in the future. Ford F150 2/96 with 3rd door.
Wow! Could not have been easier to connect my trailer harness to my Ford F150. Pull the original connector apart & snap in this "T" plug. Great item. Thanks for the [online video] for letting me know that this item was available.
Curt 56031 for a 2000 Ford F-150. Old factory connector was corroded and beyond repair.
Ordered late Monday night with 2 day shipping. Received midday Thursday . Took less than 5 minutes including cleaning my old plug off. Plugged in and zipped tied in place. Plugged trailer connector and had lights. Best money spent even with two day shipping cost. Left for the Outer Banks with boat on Friday. Hint- Used photo of my connector ends and matched to the Curt 4 way plug in photo.
This was easy to install and youtube has a good video of how to do it. The only drawback is that it does not come with a connection to the trailer hitch. I guess they just want it to be dangling beneath the truck. I went to NAPA and got one for about $5 the added a couple nuts and bolts to finish the installation. This is so much easier than splicing wires.
I bought this product to run a hitch brake light or a led light bar under my tailgate. I currently am running a hitch light. Even though it says it is for trucks without factor hoolups it plugs right in to my truck with factory 7 way. The only problem I have is the wires are so long I ran them close to the hitch and then had to zip tie a least 1ft and a half of wire toghter.
It was a direct fit and everything works according. I plan to continue shopping with this company
The product did everything it was supposed to do and was very easy to install on my F150. My existing factory installed harness left turn signal stopped working on my trailer; the problem was isolated to be the truck harness so I ordered this product. The only issue I have is minor; I wish the connector would fit in the factory installed bracket instead of swinging loose.
Cost of shipping and cost of shipping back because it is the wrong one I'm stuck with it
I ordered in-line trailer electrical kit for my 2000 F150. After attempting to get the spliced lights to work for the umpteenth time, this kit worked awesome the 1st time. Unplugged the factory plugs, plugged this in and away I went. PLUS the kit had a really long lead which is always nice. Much better than anything I could find local ...and those didn't fit.

Tim K.
9/11/2015
It rocks. You wouldnt believe the trouble I had in trying to get the generic ones to work in the past and they never did. I have never been so excited about a trailer wire..haha
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Chris
2/25/2017
Been on a year now and still works every time I plug in