Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
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2010 Mini Cooper
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2010 Mini Cooper
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Running trailer wiring usually means cutting into factory wires, but this harness avoids that. The Curt T-Connector plugs directly inline with the vehicle’s taillight wiring using factory-style connectors. It’s a clean, plug-in setup that keeps the original wiring intact and makes the job quick and simple.
Some vehicles can’t supply enough current through the tail light circuits alone. The built-in powered converter on this harness draws power directly from the vehicle’s battery, delivering consistent voltage to the trailer’s running, turn, and brake lights. That stable power helps prevent dim or flickering lights and protects sensitive vehicle electronics.
The 4-flat plug gives you the basics needed for safe towing—running lights, brake lights, and turn signals. It’s the standard trailer connection for most small and midsize trailers, so you can hook up and go without adapters or extra wiring work.
Once installed, the flat connector can be routed through an existing grommet and mounted near the hitch using a simple bracket. That setup keeps the plug secure and out of sight when not in use while giving your wiring job a neat, professional finish.
Customer Satisfaction Score:
95% were satisfied with this product
5% of customers were not satisfied
Ratings & Reviews
Thanks Roger R
The order was processed and send early. Good job!!
Easy install, works great.
Well worth it $
Easy to install, works great
It arrived in good condition. I will not open or install for a few weeks. But happy so far.
Easy install, works Great, no issues at all. Thanks for a great product.
Perfect fit with great instructions.
Very fast. Professional. Honest. The be st!
Great product! Easily combines the brake and turn signal circuits for use on the trailer.
Damn was it tough to get wiring thru the engine bay on a prius, but this was an excellent kit which made very other aspect a breeze. Highly recommend if you're looking to put a 4-flat on your Prius.
I have a 2021 Toyota prius
Turn signal turns work on trailer, but brakes or tail lights dont work
The first part of the installation went well. As for running the 12vdc line, well that was a bit of a challenge. I finally did complete the install and am content with the it. Your videos where very helpful. Toyota did not make this easy, If they had stuck with the battery in the rear, it would have been a LOT easier.
Thank You!
Very easy to install after looking at install video for Toyota Pruis 2016 to 2018. I would recommend etrailer.com to anyone. Very fast delivery, very good product, and I also got the Curt T-Connector Vehicle Wiring Harness also easy to install. Thank You etailer.com
Bought this to replace a DOA Tekonsha. I’d recommend this for the extra money over the Tekonsha as obviously Tekonsha doesn’t have adequate quality control. The trade-offs between the two are:
(a) the Tekonsha cuts brakes in at the back of the taillight, while the Curt cuts in at the combined connector behind the bumper. The latter is way easier to reach (the taillight connection point is about 2’ up inside the back corner of the bodywork), but it’s a much harder (seriously!) connector to unclip.
(b) the Curt has a shorter left turn wire, so you pretty much have to put its box behind the trunk felt instead of under the foam blocks under the trunk floor.
Install is not for faint of heart. Wish they provided more in depth on routing power wire to battery. I just ran a extra wire with wiring harness and connector to a battery on my trailer.
This connector was only partially functional on my 2019 Toyota Prius Limited. I eventually made it work after sleuthing on PriusChat.com and with etrailer.com technical support. In my case Toyota seems to have changed their wiring scheme within the main connector. I had to move two pins into different locations in the connector after which it performed perfectly. I sent pics and drawings to etrailer tech support and posted on PriusChat for any others facing this situation. Overall the installation was a chore but this wiring harness was absolutely essential to my ultimate success. Very happy with the final result.
Well designed product. The quick connectors made the wiring in the truck really easy. 3hr install due to Attack Mosquitos! The toughest part of this install was Jacking up one corner of the car. and crawling around underneath to coax the long power wire through the under-body smoothing panels.
Casey
7/31/2023
Wiring harness is still working great! Ive now been up and down the east coast with many a trailer. From little utility trailers, to 12 ft U-haul box trailers. Amazing how much a little Toyota Prius can hall. Thanks for a well built product that lasts.
I a looking forward installing this on my 2021 Prius. This one has connectors for tapping into the Prius wiring. A product I installed on my previous Prius used insulation displacing splice connectors. These didn't work because the Prius wires were too small.
Everett
6/8/2022
I have a 2021 Prius non-AWD. This did not work because Toyota changed the pin assignments on the center connector. I returned the product for refund.
This functions very well in my toyota prius extremely well for over a year. It is constantly exposed to salt water environment at least twice a week. The electricals within the vehicle are still operational! Great product and i anticipate long term future use!
Very fast service and exactly what I needed the first time. They even had an instruction video to show proper steps for every step. Very easy to follow and great customer service.
Brooke M.
3/31/2025
It's a win win for you and us when things get done right! So glad to hear this, Eddie! Here for you if anything else ever comes up :)
Easy install! The videos and customer service are top notch thank you!
I installed this at the same time as a curt kit hitch for my 2016 Prius. The videos on etrailer made this process very easy. I’d say that it took about 1-1.5 hours to install just the wiring harness. etrailer includes crimp connectors, but I followed the advice of the technicians in the videos and bought heatshrink butt connectors anywhere the wiring was spliced outside of the cockpit. I didn’t buy the trailer lighting tester they mention in their videos. I figured this is a relatively idiotproof install kit. If it doesn’t work, chances are it’s a factory issue.
I had installed a competing product and had to return it as it was designed incorrectly for my model of vehicle. Uninstalled the competing item and installed the Curt item. The Curt instructions were clear and the connectors were correct for my vehicle. The product worked on the first use and still works as required a year later. Just used my trailer a week ago without issue. Recommend this product and Brand.
The wiring harness is a perfect fit for my 2017 Toyota Prius Two. The directions were clear and the video helped tremendously. The hardest part for me was in routing the power wire to the battery under the car. Note: Since I already installed a hitch, I had to remove my rear bumper cover in order to make the lower connection. Overall, an easy install. And works as described.
Brooke M.
3/31/2025
Thanks for the tip about the bumper cover, William! I'm sure you aren't the only one who would want to start with the hitch and the heads up is nice to any future readers who haven't gotten this far yet. :)
William S.
3/30/2026
I use it for hauling my ebike when I go to the local wildlife management area. It continues to work perfect.
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Julio
12/26/2022
Still functions perfectly. No wear or corrosion. When not in use i keep the terminals covered and stowed away under my trunk mat, with the spare tire. I regularly rent unhaul trailers and i always have adequate length of wire to reach the trailer and everything powers what its supposed to.