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.
This harness skips the hassle of tapping into factory wiring. The Curt T-Connector plugs directly into existing tail light connectors, giving you a clean, no-splice install that’s ready to go almost immediately. It’s the simplest way to get trailer lighting without altering your vehicle’s electrical system.
The powered converter draws power directly from the battery through an included 15-amp in-line fuse. That setup keeps trailer lights powered without overloading the vehicle circuits. It also protects against shorts or erratic lighting, ensuring stable signals every time you tow.
A solid ground is key for proper trailer light function. This harness includes a self-tapping screw so you can make a firm connection to clean bare metal, preventing flickering or partial lighting. Once it’s grounded right, all light functions work smoothly and consistently.
The 4-way flat connector handles all standard functions—running lights, turn signals, and brake lights. It’s the common hookup for most small and midsize trailers, making it easy to connect and go whenever you’re ready to tow.
If you decide later to tow a trailer with electric brakes or need a 7-way setup, this harness is ready for that too. It pairs easily with kits like the ETBC7L to add brake controller capability without redoing your whole wiring job.
Customer Satisfaction Score:
96% were satisfied with this product
4% of customers were not satisfied
Ratings & Reviews
Works as advertised. Pretty simple install. As usual great quality product(s) from etrailer
The harness was easy to install. I did need to purchase a 4 prong socket mount so it would not hang loose from the rear of the car.
I have not installed it yet, but the order was delivered as promised and I like the fact that this item uses factory plugs instead of splicing or tapping into wires.
Flawless instructions and has worked great for over a year! Needs a bracket for the plug!
Video instructions are great. Installed it in my 2016 Audi Q5 within a couple hours. It works and is hidden when not in use. Would be five stars if the ground wire was long enough to reach the battery. I used an existing bolt to the body for ground, not the included self tapping screw The 4-way light tester is not included, but I was able to get one locally.
Still working flawlessly! Watched the YouTube videos by etrailer and it made the install easy and quick. Love things that work right the first time with zero issues.
Watched the video before it arrived, went together without any issues, just make sure you reinstall the bottom trim that has the sensor before testing for power at the plug, there won’t be any power if you have put that trim piece installed
The installation instructions are not detailed enough. Other than that, all good. Easy to install
Perfect fit for my 2013 Audi Q5
All in all, it was a very simple install for both the hitch and the lights. Would highly recommend. I do think they could have packaged it a little better, it broke through the box in shipping, but it’s a heavy hitch, so it is what it is.
This harness uses factory original plugs that interface with the vehicle's original wiring harness to make installation a breeze, quite straightforward and seamless. No janky scotchlocks, crappy crimps or poor "splice" jobs to be had here. Some disassembly required, but all the best wiring jobs do. 100% would recommend for the professional installer, although this project may be above the heads of the inexperienced DIYer.
Good product. Super easy to install. Didn’t have to cut or splice a single wire. Manufacturers instructions are vague and didn’t specify where the wires were located for the brake lights so if you don’t know your vehicle check online and you’ll find info how to install pretty much anything.
Product is great, instructions are well done. When installing however, the driver's side wiring was not long enough to mount the unit in the battery well as depicted in the instructions, and the passenger-side wiring length only allowed the wiring to be routed under the trim along the top of the hatchback (not along the scuff plate at the back of the car). The CURT instructions should be updated to make this clearer.
Shout out to etrailer! Wanted to save some money and do the wiring myself so Ed hooked me up with the right stuff and with a quick tutorial from etrailer online showing a clever and effective shortcut, I had it installed in about 30 minutes. Thanks, the hitch I purchased also installed easy with the online help. 100% will use etrailer for all my trailering needs.
I purchase the product and I try it and it was great. I didn't use it a lot of times but all the connectors was fitting very good and it is almost like factory one. That was my goal to be as closest as possible to the factory.
Be aware that the trailer lights do not work with the hatch open but otherwise easy to install and functions as intended.
Works like a charm...no cutting or splicing. I highly recommend this product.
Installation was decently straight-forward (as much as anything can be with an Audi) and sits nicely. I'm very pleased with how low-profile this hitch is. A great choice if you're looking to tow with your Q5. I will recommend accounting for how low the receiver is when you buy your ball hitch.
I did end up using it, but the install is ridiculous. I took it to the Dealer and paid ~ $500 to have it installed. The directions show routing the wires up side thru roof and into lift gate lites. And you have to dissasemble the lift gate door panels, Crazy. Even the dealer did something much simpler.
Jenny N.
3/22/2022
The installation for this harness is a detailed installation. I recommend downloading the manual from the product page as it will give step by step instructions so that you determine the difficulty.
Very easy install after watching the excellent instructional video.
I installed this connector at the same time that I installed the hitch, so the access process was halfway done already. The instructional video was a great guide, though there are a few suggestions I would make. First, Audi has many types of connectors; it would be beneficial in the video to describe how a connector is removed (squeeze the sides, press the tab, etc.). Second, the length of wire needed to run up the driver's side trim panels, around the hatch hinge, down to the lights is not sufficient if you mount the control box to the 10mm spot identified in the video. I originally mounted the control box there and when the hatch closed, the plastic cover on the driver's side hatch hinge pulled the wires tight, causing the wires to slide across the sharp edge of the cover, slicing the cover of all three wires. I ended up using the included adhesive foam mounting block to move the control box up higher in the driver's side access panel, allowing for enough slack to permit the hatch to close without stressing the wires. Hopefully, taping up the sliced wires will be a satisfactory long-term solution as the wiring is functioning as expected now. Third, I was able to attach the ground wire for the control box to a 10mm stud located right next to the place that the video suggested drilling the self-tapping screw, I was hesitant to put a new hole in metal that close to the wheel well. Finally, after the installation was complete, I received a lighting system error code, after a little playing around with connecting, disconnecting, turing the car on and off, and resetting the error codes via OBD2 (using Carista), the error cleared and everything worked. I don't know exactly what resolved the problem, but I spent about 45 minutes troubelshooting before it worked.
Everything worked with Audi's electrical system.
Outstanding!
Nevin
3/23/2026
So far - So Good. All the components fit and work.
I installed the Curt trailer wiring kit right after I installed my hitch, so some of the access points were already open. If you follow directions and install the converter in the battery compartment, the wiring harness to the tail lights will be too short. I installed the converter in the driver side compartment where the air compressor rides and ran the power wire only to the battery compartment. This provided barely enough length to reach the tail light wiring connectors in the lift gate. Other than that, I followed the directions and everything looks good, all the wiring is hidden behind trim panels, and the harness works great.
Bob
7/26/2022
Easy as advertised and I still like it.
Plug and play wiring, couldn’t possibly be a simpler installation.
Easy install. I did cheat by fishing the wire through the panels.
Kent
8/29/2026
Still working great. Very easy installation.
Jerred H.
8/29/2026
Do you have a question about this Custom Fit Vehicle Wiring?
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.
Andrew
10/18/2022
Still working as advertised, happy as can be.