To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.
Wiring a trailer doesn’t have to mean cutting into factory wires. This Curt T-Connector uses a plug-in design that ties straight into the vehicle’s existing connectors. No splicing or guesswork—just match the plugs and it’s ready to go. The hidden layout keeps everything neat behind the trim for a clean, factory-style look.
Some vehicles can’t handle the extra load from trailer lights, but this harness has a powered converter built in to protect the electrical system. It delivers consistent power to the trailer’s running, turn, and brake lights without drawing too much from the vehicle circuits. That means steady light signals and less risk of wiring faults over time.
The harness ends with a 4-pole flat connector that gives you all the basics—running lights, turn signals, and brake lights. It’s the most common style for small and mid-size trailers, so it’s ready to hook up right away. Once connected, the molded plug sits securely and keeps out moisture for dependable use on the road.
If your vehicle didn’t come with a tow package, this kit fills in what’s missing. The plug-and-lead setup provides every circuit needed for trailer lighting without relying on factory tow wiring. It’s an easy way to make your vehicle tow-ready without any custom wiring work.

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hi, everybody, Andy here with etrailer.com. Let's take a real quick look at this CURT T-connector vehicle wiring harness with four-pole flat trailer connector. Now, this wiring harness has been designed to fit your 2011 to 2013 Ford Fiesta Hatchback and then your 2009 to 2010 Lincoln MKS. On custom-fit parts such as this wiring harness, I do recommend taking advantage of our vehicle fit guide here at etrailer.com. Simply enter the year, make, and model of your vehicle and our fit guide will confirm if this will work for you or if we have something comparable that will work for you. So this harness is going to give you this four-pole flat trailer connector at the back of your vehicle to power your trailer signal lights.
This is also going to be compatible with five, six, and seven-pole adapters, which are sold separately. If you notice, a dust cap is included for the four-pole flat connector, and that's gonna cover up those connection points when this plug is not in use. Now, the black box on this harness is a powered taillight converter, and this is going to make sure that your vehicle's wiring matches out of your trailer. This will connect directly to your vehicle's battery to avoid overloading its electrical system, reducing strain on your vehicle's wiring system. By the way, CURT does build each converter using surface mount technology for consistent, reliable performance.
It's gonna maximize trailer light yield and intensity while producing minimal heat, ensuring superior operation even in rough road conditions. Now, this harness is designed to connect quickly and easily. You will need to locate your vehicle's wiring harness, which is gonna be located behind the driver's side and passenger side interior trim panels in your rear cargo area. But once you locate those connectors, you're gonna separate them and you wanna be careful not to break the locking tabs. And then you're going to insert these T-connector ends between your vehicle's wiring connectors and then lock them into place.
These T-connectors are custom-fitted for your vehicle, so they're gonna match up perfectly with the connection points on your vehicle and they're gonna snap and lock together for a tight, secure fit. Once you have these plugged in, you will need to make a good ground connection. And the ground wire is this white wire. And if you notice, it does have a ring terminal attached to it and it does come with the self-tapping screw. So you can get this installed and grounded into a suitable location such as your vehicles cross frame, vehicles frame rather, or cross member.
You just wanna make sure that the surface is clean and rust-free. Then you want to mount this converter box to a safe out-of-the-way location, and you can do that a number of different ways. It does come with double-sided tape, but that might hold it for a while. I don't think it would hold it when the temperatures start to rise. It might start to come off. So you could use one of the many cable ties that's included with the kit as well to secure this along with a double-sided tape. However you do that, you just wanna make sure that it's mounted and it's out of the way and it's going to be secure. Next, you're going to need to run this hot lead to your vehicle's battery. That's this short black wire that's coming out of this converter box. This short black wire is going to get connected to one end of this included bundle of black wire using one of the included butt connectors. And then the other end of this bundle is going to get routed to your vehicle's battery. And once you have that other end routed to the battery, you're gonna take this fuse holder and you're going to connect one of the wires with the second included butt connector to the routed end of this bundle of black wire. And then you'll take the second wire of the fuse holder and you'll connect this ring terminal attached to it. And then that ring terminal will get attached to the positive post of your vehicle's battery. Now, this does come with a, let me see if I can read the amperage on this fuse. This is a 10 amp fuse, so it does come with this 10 amp fuse and then you'll just pop it into this fuse holder after you have it wired up. And then if you notice, it has a cap on there to keep that fuse safe and protected. So you're gonna be able to secure any excess or slack in your wiring. Again, with the cable ties, it's included with this kit. Instructions are also included to guide you through that installation process, going in quite a bit more detail than what we we inchesre able to do today for our demonstration purposes. And then once installation is complete, the 4-way connector will be stowed in an out of the way location within your cargo area. Now, it is also recommended that you use a small amount of dielectric grease on all of your electrical connections, like the plugs on the vehicle end and the four-pole connector itself. That grease is designed to help prevent electrical failures caused by corrosion and moisture. So on your screen, I am including our item number for that grease. You can just take that item number, pop it in the search field of our website. That will take you to that grease and you can add that to your order. Well, that's gonna wrap up our look today. I do hope that it was helpful for you. Again, my name is Andy. Thank you for joining me.
Customer Satisfaction Score:
93% were satisfied with this product
7% of customers were not satisfied
Ratings & Reviews
Product is very good and service was very good.
As advertised easily installed
Everything fit nicely and as advertised. Very happy with stuff.
EVERYTHING WORKED GREAT.
On this product I felt that the pictures that were sent in the diagrams weren’t adequate because my wiring looked different than what the picture showed took me a while to figure it out it installed OK and works fine
Was surprised that the wires did not get compromised since it runs through the hatch back seal and the door technically closes on when it’s used but it has not show any signs of failing yet so yea quite impressed to this point.
This Curt trailer hitch fit my 2010 Lincoln MKS perfect, I did watch the video provided by etrailer.com two weeks before receiving the hitch and Curt wiring harness. Currently haven't installed the pigtail harness and just using the hitch for my recumbent trike. Once again etrailer.com came through for me delivering another well deserved 5 star rating!!!
Info for this part was:
At etrailer we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.




Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.
Error submitting comment. Please try again momentarily.