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Trailer wiring doesn’t have to mean cutting into your vehicle’s factory wiring. The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector plugs directly into existing tail light connectors. The plug-and-play design keeps the install clean and simple, with no splicing or guesswork involved. Just connect the matching plugs behind each tail light, route the power wire, and the harness is ready to go.
This harness uses a powered converter that draws power straight from the battery instead of the vehicle’s lighting circuits. That design keeps the trailer lights working without overloading or damaging sensitive vehicle electronics. The converter isolates the trailer’s electrical load so the lighting system stays protected even when towing in rough conditions.
The kit comes with 20 feet of 12-gauge power wire to connect directly to the positive battery post. That heavy-duty wire ensures a solid 12-volt feed to the converter for steady trailer light performance. Running a dedicated line from the battery also helps prevent dim lights and blown fuses from shared circuits.
Some vehicles use advanced LED tail lamps that can confuse basic trailer harnesses. This Curt powered system works properly with LED configurations, providing clean signals for running lights, turn signals, and brake lights through its standard 4-flat connector.
At the back, the harness provides a 4-pole flat connector that delivers all the basics—running lights, turn signals, and brake lights. It’s the standard plug used on most small and medium trailers, so you can hook up right away without extra adapters.
Customer Satisfaction Score:
96% were satisfied with this product
4% of customers were not satisfied
Ratings & Reviews
Matthew M.
10/12/2017
Same
Kevin H.
10/11/2021
All is still working after 1 year, although I have only used it a few times in a year. The cap on the wiring attachment broke where it is attached to the wire, but I just stuck it on the exposed attachment.
Hwh
4/8/2018
After a year the Curt T-Connector wiring harness with 4-pole trailer connector C56165 has been working great with no problems or issues.
Howard
8/16/2019
After one year, no problems. Recommend product.
Earon S.
2/27/2018
The trailer hitch and wiring adapter are working great. The money I save buying and installing the trailer hitch over having someone else do the installation was tremendously helpful on my budget.
Htk
6/7/2016
They are performing fine
Al C.
4/11/2016
No problems installing and works just fine. No complaints at all.
Jenny N.
12/3/2021
I recommend being sure to watch the video install that we have on a 2011 Toyota Rav 4 that I have linked below. Be sure to remove the scuff panel like at mark 1:00 and also all the side panels and trim fasteners like at marl 1:40 and 2:40 to gain the room needed to pull the wiring across. Then pull the red and green side through the side panel and across like at mark 3:19. This will give you the best maneuverability and room for installation.
Helpful Links
Jon
2/6/2023
I have had no problems with my trailer wiring. Im very happy with my purchase. I do recommend you to people i talk to. I am considering trading the toyota so, im sure i will be back for a wiring kit to put on the replacement.
Sandra S.
2/9/2018
Still happy with it and it works fine. There have been no issues!!!
Ajayz
9/16/2018
Wiring harness still working like a champ!
Barak B.
4/29/2015
Great product, install was quick and painless to this day it works very well
Barak B.
5/8/2015
Thank you for the email. I use them plenty and the fit work well. Something for your team is to find a way to keep it from rusting so soon. I get that when the paint rubs off the metal becomes exposed to the elements, however, could there be a way that it doesnt rust so fast? It was almost instantaneously that rust appeared after the first time I used the safety chain loops and now it is pealing away from there. Please understand I am not looking for anything in return, just some feedback for the future.
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Richard
7/24/2026
Still working as promised! I use it a dozen times a year at a minimum and I never gave an issue! Highly recommend!