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This Curt T-Connector harness plugs right into the factory tail light connectors, so there’s no need to cut or splice wires. The setup is simple and clean, giving you a 4-pole flat trailer connector ready for towing lights. It’s built as a complete plug-in kit, so you can get it installed quickly and avoid wiring guesswork.
The integrated converter keeps your vehicle’s lighting circuits protected while running your trailer lights. It handles up to 3 amps per circuit for stop/turn functions and 7.5 amps per circuit for running lights. That makes it a solid match for trailers with LED or standard incandescent lights, keeping everything working smoothly without overloads or blown fuses.
The harness is designed to use the vehicle ground for a stable connection, reducing the risk of weak or flickering signals. Proper grounding ensures your brake and turn signals stay bright and consistent even when headlights are on, helping avoid the odd light behavior that can happen with poor trailer grounds.
Each side of the harness uses weather-tight connectors that lock firmly into place behind the tail lights. That tight fit helps prevent corrosion or loose pins that could cause intermittent issues down the road. Once connected, the harness stays out of sight and protected while delivering dependable trailer lighting every time you tow.
Customer Satisfaction Score:
94% were satisfied with this product
6% of customers were not satisfied
Ratings & Reviews
The trailer hitch's fit was excellent. Also the wiring harness installed very easily. My only problem was that the weld nuts in the frame were very rusted and it took quite a lot of time with a wire tube brush to get them cleaned out so that the bolts would install. Once they were clean, the installation was every easy. 2007 Corolla S.
(Oops. Provided the wrong review for this product). My neighbor hooked up the wiring and used to do it all the time, so it was just a matter of pushing it under a rubber overlay at the back under the rear door, and under the carpeting to curl up in the opening for the tail lights. When I do hook it up, it should be a simple matter to attach the loose plugs to the trailer, but, haven't done it yet!
Product arrived at scheduled time. All pieces ordered were properly and securely packed so no damage occurred during shipping process. Quality of products is great. Read installation instructions and believe the trailer hitch and wiring kit will be easy to install. This particular hitch will be mounted to my 2006 Toyota Corolla to pull a vintage 1985 light sailboat.
Has been working great for a year now. I can easily hide the cables in the spare tire compartment in my trunk when not in use. It's def possible to slip it through the bumper and into the tow-hitch if you don't mind doing a bit of mod work to your car. Highly recommended.
This wire loom really simplifies wiring up a trailer connection. Super simple to install and makes a trustworthy connection without splicing into the cars taillight loom. Took me longer to unclip the small factory clips than it took to install this kit. Save yourself money and frustration and buy this kit!
Perfect fit, quality hardware, excellent price, simple install.
Took 45 minutes to install the wiring harness & trailer hitch - piece of cake.
No locating and cutting wires - remove (2) electrical connectors and snap in the connectors on the wiring harness, put in a few wire ties to make it neat, clean, and professional looking, reinstall the panels, and done.
The only glitch was the instructions called for connecting a grounding wire which was not a part of the wiring harness and also not necessary.
Highly recommended! Probably saved ~ $150 versus getting it done elsewhere.
I seem to have intermittent connection issues with the plug in tom the trailer , May be more trailer related but can't say it isn't the harness.
I ordered this rush shipping when my old harness (never tested that one, truly) wasnt working, and Uhaul had marked it up to corrosion. etrailer came through on rush delivery.
Sadly, my issue persisted with a new harness. My vehicle lights all work and worked perfectly, and I even tried reversing the harness left to right.
The harness does not turn on my running lights. When I hit brakes, I can get running lights. Turns/hazards dont work. I gave up. Same trailer or lighted carrier used on other vehicles and worked perfectly. Maybe something was done differently with my car at the factory. In the end we chose to only use the hitch carrier in the daylight on the corolla, and made sure all vehicle lights were visible around the cargo.
Vehicle is a 2006 Toyota Corolla CE, stick shift.
Plug and play perfect install took only 30mins on a 2010 toyota corolla instructions calls to take white wire and ground using a self tapper screw provided with an eyelet (INCORRECT) skip step 5 its grounded thru the harness connection.
Mike L.
4/15/2026
Sorry for the confusion Brian, it looks like Curt upgraded the harness but forgot to update the instructions!
this is a very good product allows you to attach the trailer wiring without cutting your vehicles wiring . it sounds like a minor detail but it is not .it is always best to protect the integrity of your vehicles wiring . very happy with the product and the people at e trailer
Mark S.
3/12/2017
the trailer hitch and wiring are both working well for us after about a years use . after having this thing for awhile i find it is just what i needed . i like the fact that when it is not being used the wiring goes in the trunk out of the weather .
The wiring harness I ordered with the trailer hitch was somewhat confusing. The online installation video stated the wiring harness required no wire cutting and the harness simply plugged into place. The instructions that came with the harness I got stated:""Locate a suitable grounding point near the connector such as an existing screw with a nut in the vehicle frame or drill a 3/32" pilot hole for the provided screw. The area should be free of rust, dirt and paint. Secure the white ground wire using the ring terminal and provided screw." My wiring harness did not have a white grounding wire, a ring terminal and screw. I assumed I had been sent either the wrong wiring harness or incorrect instructions. It was very confusing. I emailed the company concerning this and got no response. I was just about to send the hitch and harness back and try another company when I decided to call eTrailer and was finally told that I did have the correct wiring harness and that the instructions were incorrect. This company failed in providing correct information that could have resulted in a sales lost, electrical damage to my car and trailer. This company failed in contacting me in a reasonable time frame.
Katrina B.
3/10/2023
This harness grounds through the wiring on the vehicle that the vehicle manufacturer would have run. Youre just supposed to plug the wires in.
I can't claim all the credit for adding it. I did get a little help from my mechanic. I had some issues installing the hitch itself and needed his expertise to tap out the holes to mount it. When he did that he also connected the wiring harness, however it went easy and everything works fine now! Thanks
Raymond
6/1/2019
still working fine!
Hardest part was getting the connector apart on the car.
Then is was 14 minutes to be ready for check out of the lights
on the boat trailer. Perfect......
Installed the Curt Wiring Harness on my Toyota Corolla and it fit and worked perfectly. Very simple installation- plug and play.
Great service from etrailer- highly recommend them as well- fast delivery.
Anthony S.
4/24/2018
After being used numerous times over the past year, the wiring harness is still working trouble free. Couldnt be happier with this product.
Wiring harness fits and works perfectly. Fast shipping.
Great product
Thanks to the Etrailer's install video, it simply couldn't have been easier.
After a year, still working great. I purchased with the “custom” pigtails that plug directly into the existing harness, and haven’t had to mess with anything after the install.
Installation was a breeze on a 2007 Corolla, video instructions were short and clear. Design was great, not having to run a power wire under the car and to the battery was a huge plus.
THe Curt Trailer harness was exceptinal. Good Quality; easy to install. At an affordable price.
Alvin
7/23/2025
PerfectlyIt was a easy install and performs flawlessly.
Best customer service in the business !
Put this on my 2010 Corolla (5 speed manual) for a bike rack and to tow a small motorcycle trailer.
Was easy to install by myself on this vehicle (has pre-drilled holes and don't have to drop the muffler).
Have done 2 300 mile-ish mountain towing runs with the motorcycle loaded up with no issues.
Would recommend!
Ryan
12/1/2020
Still no issues. Solid hitch
Good Customer Service!! Brittany K was very helpful and informative. I ordered two of this item. I installed one today very easy it took me bout 10-15 mins. I’m ready to haul a trailer for camping.
Victoria H.
1/16/2025
That's awesome Aden, I'll let Brittany know you reached out! Do you have a photo of your camping set up you can share?
WOW perfect 15 minutes and done plug and play
Phone service exceeded my expectations
Excellent packing and quick delivery
No splicing needed. Plugged right into existing connections. Just wish the harness to the box was a hair longer for better mounting on a flat surface but still a non-issue.
Do you have a question about this Custom Fit Vehicle Wiring?
Info for this part was:
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Mike L.
2/18/2019
When theres an intermittent trailer lamp problem, most of the time it can be traced to a ground problem. Make sure the wiring harness is correctly installed on the vehicle, according to the installation instructions. Make sure the connectors are pushed together until they click. On the trailer, be sure that the ground connection to the trailer frame usually made on the trailer tongue is secure and not corroded. Make sure each lamp is grounded either by its mounting hardware being in direct contact with the trailer fame or by its ground wire being connected to the trailer frame. Ill link you to some help articles that will assist in your troubleshooting.
Helpful Links
faq-4-5-way-troubleshooting.aspx
faq-wiring.aspx