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Wiring a trailer can be tricky, but this Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector takes the hassle out of it. It plugs directly into the factory tail light connectors, so there’s no need to cut or splice wires. The converter box protects your vehicle’s wiring and supplies the power needed for proper trailer light operation.
Some vehicles can’t handle the extra load from trailer lights on their own circuits. This harness draws power straight from the battery through its powered converter, keeping the vehicle’s tail light system safe. The converter isolates and powers the trailer lights without overloading factory wiring, helping to prevent shorts or blown fuses.
The 4-flat connector gives you all standard lighting functions—running, brake, and turn signals—so your trailer stays visible and compliant on the road. The connector routes cleanly outside the hatch for easy access when towing, and it pairs well with an optional mounting bracket for a tidy setup.
Good grounding is key for consistent lighting, and this harness includes a dedicated ground wire designed for a clean, secure metal-to-metal contact. The high-quality connectors resist corrosion and ensure a tight fit, giving you dependable power delivery every time you hook up your trailer.
The harness installs behind each tail light and then runs a single power wire to the battery. It’s straightforward to route and secure, allowing you to finish the job with standard tools. Once installed, you’re ready to tow with confidence knowing your trailer lights will work exactly as they should.
Customer Satisfaction Score:
96% were satisfied with this product
4% of customers were not satisfied
Ratings & Reviews
Went on quick and easy. wireing harness worked out good too
Wiring Harness was very easy and quick to install and after a year on the vehicle there have been no issues. Product did arrive fairly quickly also. Seems to hold up well with salty conditions of our winter too
The directions are so easy to follow to install this wiring harness. Product is made of quality parts.
Little difficulty running power wire. Wish it was a little more plug and play. However worked very well once installed
The drivers side was made way too short. The power converter black box was up inside the fender area without any way to fasten it to vehicle. On another day, I will probably end up cutting the harness and extending the wiring somewhere between 6-10 inches at least.
I got it to work... wire lengths weren’t optimal for a 2016 Tucson. The harness for the drivers side was a bit short forcing me to mount the controller in an awkward place.
Simple installation!
All the connectors fit together as intended.
It's been installed for over a year without any issues.
Everything was included that was needed for the install. For some reason my vehicle needs a wire that runs from the rear of the car all the way up to the positive side of the battery terminal under the hood, which makes it a separate circuit with its own fuse. By removing the lower black plastic molding under the doors the wire can be neatly tucked inside for most of the way.
works great.
Directions were a little confusing but overall not bad. Not the easiest hookup but was on a new 2016 hyundai tuscon. I would recommend this wire harness again especially if someone has some knowledge of cars. Not for the guy who cant change his own oil or air filter, it would be too complicated.
This is the third trailer wiring harness I have bought from e-trailer...Installed fine and works perfect....
Overall the product does what it is desgined to do however 2 tips would be the wire to the drivers side light needs to be atleast 1ft longer and you should probably mount the box to the frame the double sided tape wasn't enough. But in order to do that you need the drivers side wire to be longer otherwise its up in the body of the car. But otherwise works as planned.
It was a great fit Thanks
The wiring kit for my 2017 Hyundai Tuscon, that was very easy to install. I also ordered the hitch from here, bolted it on by myself, the whole thing didn't take long at all.
Best site I’ve found for trailer hitches. Videos are very helpful. Hitch and wiring install was straightforward. No issues.
So easy to install! The wiring harnesses interfaced perfectly with the car lights for a super simple connection. Plenty of extra length to allow you to position the connectors however you needed.
Overall not to bad, but not like in the youube video. The wires are to short on the passenger side of the car. When you plug in to wires at the tail light the wires that go to the junction box are about 18" to short. There is no way to mount the box on the frame like they show in the video. I just left it inside below the light fixture dangling, hopefully it will work over a period of time. I guess I could have spiced extensions on the wires but for what you pay for this light kit, it seems they are a little chinsey on the wire length. Plenty of green wire going over to the passenger side tail light. At least everything fit!
Aftermarket wiring harnesses can be frustrating. I don’t enjoy mechanic work but I removed taillights and ran wire according to the instructions. After repairing a bad connection, everything worked. Then, my lights began to short out and malfunction on a trip. It turns out that the main wire going to the plug wore through and was touching metal. I ordered another identical kit but placed the wire in plastic automotive conduit before routing it underneath my vehicle. It’s been great ever since. Spend the extra time and money to do it right.
Easy to follow instructions, quality materials and everything included .
It’s a little more tucked away than I thought it was gonna be but it still looks great !
It works, no directions included but not to hard to figure out
All good great product great timing on shipping
Wiring harness fit was excellent. I watched the installation video you provided, very helpful.
Easy install, plug n play to its max very easy to follow the instructions and videos
Easy install if you follow along with the video. Lots of crawling around under the car if you don't have a lift, but nothing particularly difficult, just awkward. I saw others complain about the short wires on the driver's side tail light connector but I didn't think it was bad. Also comes with plenty of zip ties if you route the wire the way they do in the installation video, but if you don't loosen the panel to tuck it in with the main wiring harness I could see how you might need more.
Direct fit, plug and play. Wiring correct length. Great product.
Dillon
3/22/2026
A year into owning this harness, still performs great. Use it every other weekend with either a 8ft trailer or a custom hitch rack with lights.
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Steve
5/5/2025
Excellent