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Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance.
Features:
Specs:
Installation
This custom-fit T-connector plugs into your vehicle's wiring harness, which is located in your rear cargo area. You will have to remove the trunk floor covers, storage trays, sub woofer, spare tire, scuff panel, and interior side panels to access this harness. Once you've plugged in the T-connector, run the hot lead up to your car battery. Connect the lead to the included fuse holder, and then connect the fuse holder to the positive terminal on your battery.
Once installation is complete, the 4-way connector will be stowed in an out-of-the-way location within your trunk.
It is recommended that you use a small amount of grease on all electrical connections - the plugs on your automobile and the 4-pole connector itself - to help prevent corrosion.
A tail light converter is built into this T-connector. This converter is a circuit-protected, battery-powered unit that bypasses the electrical routes that are used by a basic wiring harness. As a result, there is virtually no draw on your tail light circuits.
Curt builds each tail light converter using surface-mount technology (SMT). This method of construction involves soldering electronic components directly to the surface of a printed circuit board. SMT eliminates the need for leads, which are used in older through-hole technology. The result is a circuit board that is smaller yet provides more routing area and that offers superior performance, reliability and durability.
Circuit boards constructed using SMT have been shown to perform better under rough conditions with excessive vibration than those made using the through-hole method. And where would vibration be more likely to occur than in towing applications? Curt converters also produce less heat, leading to increased durability and longer life. In addition, lower levels of resistance ensure better performance, especially for parts that operate at higher frequencies.
Each Curt circuit board is made using high-quality components that are pieced together in the most technologically savvy fashion, leading to greater predictability and reliability in functioning.
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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.
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.
Easy install. I did cheat by fishing the wire through the panels.
Very easy install after watching the excellent instructional video.
Works like a charm...no cutting or splicing. I highly recommend this product.
Everything worked with Audi's electrical system.
Outstanding!
Perfect fit for my 2013 Audi Q5
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
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.
Made the install really easy.

Daniel
11/1/2024
Wiring set made the installation process a breeze. Works really well and provides a strong signal
Works great, a little more in depth than some other vehicles but what isn’t on an Audi. It’s worked great for me so far
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.
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.
The wiring harness didn't work.

Gwendolyn Y.
4/29/2025
Hey Thomas. I'm sorry to hear that the harness didn't work. Were the plugs not right or are you having power issues? I want to help out so you have a working harness for your trailer. Let me know when you can.

Be aware that the trailer lights do not work with the hatch open but otherwise easy to install and functions as intended.

Andrew
10/18/2022
Still working as advertised, happy as can be.
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.
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.
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.
The installation instructions are not detailed enough. Other than that, all good. Easy to install
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.
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.
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Bob
7/26/2022
Easy as advertised and I still like it.