To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.
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.
Wiring a trailer doesn’t have to mean cutting into factory wires. The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector plugs directly into existing tail light connectors. It’s a clean, hidden install that taps into the vehicle’s wiring without splicing or modifying anything. Once it’s plugged in, you have a ready-to-use 4-flat connector for your trailer lights.
This harness uses a powered converter that pulls power straight from the vehicle battery through a 12-gauge wire. That design keeps the vehicle’s sensitive electronics protected from shorts or overloads that might occur on the trailer wiring. The tail light circuit only sends signal information, while the actual power comes from the battery, providing stable current to the trailer lights and safeguarding factory systems.
LED lights on either the tow vehicle or trailer won’t pose a problem here. The harness uses its own power feed and signal converter so it can handle the low current draw of LEDs without issues. It provides smooth operation whether your trailer uses LED or incandescent bulbs, keeping turn, brake, and running lights working consistently.
The built-in 4-flat plug delivers all the essential lighting functions—running lights, turn signals, and brake lights—for most trailers. It’s the standard connection style found on small utility trailers, campers, and boat trailers, making it easy to hook up and go once installed.
Customer Satisfaction Score:
96% were satisfied with this product
4% of customers were not satisfied
Ratings & Reviews
The wiring worked good, I am glad this is available to hook the turn signals and brake lights up on these new vehicles. Wire harness is different on these new cars, not like the old days,,
Great for my needs
The trailer hitch works great. It was easy to install.
The wiring harness was easy to install but i went threw the firewall instead of going under the vehicle.
Installation was easy. I have use the trailer connector a lot in the last year on my Ford Transit Connect with my own trailer and U-Haul trailers. Worked flawlessly. I would recommend to anyone needing trailer light wiring to purchase this item.
The Curt wiring kit all went together easily. I put the module on the R side vs L. I had power on the R already and had a convenient grommet to drop the trailer plug wiring thru for a permanent installation using the Curt flat 4 bracket. Doing this tho I needed to reverse the R and L turn wires and all worked well. Works great!
Fast delivery!
The installation was not difficult, it went well. Watched videos from etrailer.com links, had no problems, all good fit. My only deviation from instructions was to run the 12 volt supply through the inside of the van to an existing relay. I keep it tucked into the jack compartment, pull it out when needed. Happy with this purchase.
All issues with putting this in go on Ford for making the light couplings hard to get at. Got it done and works well.
This is an excellent product and everything fit nicely together. This product was used on a 2017 Ford Transit Connect XLT 7 passenger wagon. It was somewhat difficult to install on this vehicle as the rear access panels alone did not provide sufficient room to access the connectors. We had to partially remove the right rear and left rear panels by popping the plastic retaining pins out in order to pull the back panels far enough out to access the connectors. The rear seats do get in the way but assembly can be made by having a helper flex panels back far enough to access connectors without damaging panels. We followed the video provided by etrailer completely with the exception we ran the power wire up over and behind the insulated wheel well material on driver side rear wheel rather than down brake line and under heat shield. We also added plastic conduit to protect power wire from battery down to where it enters body leading to back. Total time took about 3 hours with two people and of course with not elevating vehicle. I advise at least 6 inch elevation.
I installed the hitch, but had an accessories place put the wiring in as part of another customization. I was a little spooked when I opened the instructions, said I'd have to run the ground wire all the way to the front, to the battery, (gulp! on my new car!) but I didn't recall seeing any note about why it can't just ground to the frame or something else nearby, so, though I bolted the receiver on no-brainer when I got the package a year ago, I had them do the electrical installation just a few weeks ago, as they're better set up to route and feed that ground wire. The hitch section has no issues, installation went absolutely by the book, no surprises. As far as I know no problems with any of the harness installation. I will say, I particularly like the large safety chain attach loops on these newer receiver models, much easier to feed the safety chain than other receivers I've gotten from these guys. Over the years when I've needed trailer stuff, I don't shop anywhere else.
Was a perfect fit for my vehicle in every respect. All parts needed were included and worked perfectly after installation. The videos of my vehicle were a big help. The tail light connectors are hard to get to but thats on Ford. Was also hard to run power wire under the van to the battery keeping it protected from rocks, hot exhaust and moving parts. But blame that on uni-body construction. I was able to do a good job, just took a while. Wish Ford included towing wiring as standard. This Kit is excellent.
Worked great, and if I watched the install all the way through the first time it would have taken a quarter the time.
I was kept informed of orders progress and was able to track it within 2hrs of delivery. Shipper did an excelant job box looked like new and product was in excelant shape when unpacked. Great how to instruction I read twice and checked under vehicle for corresponding access points. It went together in 16 mins and I didn't even jack up the vehicle. E trailer has great products with great staff and support. Well done crew!
Jerry A.
12/27/2015
Product still performs flawlessly
Had my mechanic install, works great a year later!
I am very pleased with my Curt T-Connector wiring harness, this is about the fourth curt wiring harness I've installed and I am installing it very soon.
Directions were easy to follow. Easy to hook up except for the main power wire which had to be routed to the battery. but, doable and works great
This would be 5 stars but I took one star because I had to get a mechanic to fix my home install. Turns out, the whole time I could have tied in the power to a power outlet in the back of the van - I never needed to find a way to feed the power wire all the way up through the bottom of the van. Would have saved me $150.
I love the etrailer it only took me 55 minutes to install I watched a how to video it was a great help , thank you very much
I had a great experience with etrailer. The trailer wiring harness I ordered fit my vehicle perfectly and was super easy to install. Everything works exactly as it should — no issues at all. The product seems well made, and it was packaged nicely.
What really stood out was the service from etrailer — fast shipping, clear instructions, and great communication throughout the process. I’ll definitely be using them again for future trailer or towing needs!
This fixed out U-Haul connector problem
ive never come across a receiver with 2 different size pin holes till yesterday after i got it hung! pin wouldnt go all the way thru to put the hair pin in it. how does THAT,happen???
Ordered a knock off plug and play online and after receiving 2 that didn’t function correctly but each with different issues, purchased the Curt and it was perfect
Love the product. Good integration with the vehicle wiring harness. The kit came with good accessories for mounting and wire management. One downside was the instruction to run a power line to the vehicle battery under the car. With the transit connect van, you have a fuse box near the rear passenger door, so makes more sense to go there for power. See pic of empty fuse slot used for power source.
Nick S.
9/29/2025
I am glad the installation was easy, and great point with the fuse box, I did not know that so I will keep that in mind moving forward! I am sure those photos will help many others in the future. What are you towing behind that Transit?
Works good. Needed about 5 more feet of black battery cord. Sad that Curt goes cheap and doesn't include the mounting bracket. Corner cut for sure. Being that the price of the bracket is 5$ and the screws are $1 (not to mention what they buy it for from China), pretty sad that you get nickeled and dimed.
Trevor
4/3/2026
Seems to be working just fine.
Excellent quality wiring harness! Installation was very easy, and everything plugged directly into the factory connectors with no cutting or splicing required.
One thing to note is that you do need to run the power wire to the battery for proper operation. However, on my Ford there is a 12V power outlet in the rear cargo area, so I connected the power wire there instead, which made the installation even easier.
I’m very happy with this product and highly recommend it to anyone looking for a clean, factory-style installation.
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.
Gordon
6/28/2025
Still going strong, zero issues.