T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
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2012 Ram 1500
These items fit your vehicle
2012 Ram 1500
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Tired of complicated wiring? Say goodbye to cutting, splicing, or tapping with the T-One Vehicle Wiring Harness. It plugs directly into your vehicle's existing wiring, making installation quick and stress-free. Just connect the plug, and you're good to go.
Worried about overloading your vehicle's electrical system? The built-in ModuLite Converter draws power straight from your battery, protecting your car's wiring. This ensures seamless compatibility between your vehicle's three-wire system and your trailer's two-wire system, with no extra burden on your tail light circuits.
This harness is custom-designed for a perfect fit, ensuring that it interfaces seamlessly with vehicles equipped with a factory towing package. Crafted for precision, it matches the specific contours and electrical needs of your vehicle.
Keeping electrical connections clean is crucial for longevity. A dust cap comes included to protect your 4-way flat connector from dirt and debris, ensuring reliable connections every time you tow.
Have multiple trailers? No problem. This wiring harness is compatible with 5-pole, 6-pole, and 7-pole adapters, giving you the flexibility to easily switch between different trailers without hassle.
This custom-fit T-One connector plugs into your vehicle's wiring harness, which is located behind the driver's-side interior trim panel in your rear cargo area.
Once installation is complete, the 4-way flat connector will be stowed beneath your vehicle, near the trailer hitch. A mounting bracket (sold separately) is recommended to keep the connector secure.
It is recommended that you use a small amount of grease on all electrical connections - the plug on your automobile and the 4-pole connector itself - to help prevent corrosion.
A ModuLite power module is built into this T-One connector. Because most trailers run on a two-wire system - wherein the brake and turn signals are carried on one wire - the separate brake and turn signals from your vehicle's three-wire system need to be combined so they are compatible with the wiring system of your trailer. This power module functions as a tail light converter to combine the brake and turn signal functions of your automobile so that they run on one wire to properly activate your trailer's tail lights.
This will not affect how the tail lights on your vehicle operate.
With a ModuLite, your trailer's lights will be powered without overloading your vehicle's electrical system. Because the module draws power directly from your car's battery and bypasses the electrical routes that are used by a basic wiring harness, there is virtually no draw on your tail light circuits.
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The trailer hitch and wiring harness was as described. I was able to install both items myself after watching the installation videos. The items arrived on time and undamaged. I would purchase from this seller again. I had a question about my order and their customer service was able to take care of my issue without transferring me to other agents. Overall, I received excellent service.
So easy to install. I did the hitch and the wiring harness in about 45 minutes.
Works perfectly.
Very easy installation. The only hangup was having to research my owners manual and find that the factory does not install fuses for a tow package.
I went to the auto parts store picked up some fuses put them in , and it’s perfect.
Need to work on packaging. Both bracket ends and the receiver had burst through the box and were missing paint. Shipping was quick. Installation was easy, fit me t was good.
so easy to connect. at first i ordered the universal but was able to return it after shipping charges for this that just plugged right in this is exactly what i needed
Worked right the very first time I plugged it in. Easy to mount, easy to route. Well worth the price.
Etrailer installed it, so I don't have anything to say about that. It works. Light come on and go off on the trailer when they are supposed to.
Easy to determine that I had the proper harness. Easy to order. Delivery was prompt. Installation a breeze.
A real plug and play worked perfectly on my santa cruz .saw it on you utube
This hitch is great! I installed it myself with basic tools. The wiring harness made it easy.
Ben 
12/29/2024
I tow a utility trailer often with the hitch. I’ve never had any issues with wiring. I live in FL so no rust either. I remember the customer service and online video made this a no brained.
Easy plug-and-play installation. Exactly as described. Plugs right in without any issues.
Part does not fit a 2025 Hyundai Tucson. Please advise how to return it.
Plug and play just like advertised
Great product, easy installation and works perfectly
BEWARE. OPEN BOX ELECTRICAL COMPONENTS BEING SOLD AS NEW.
Looking at the online video showing a similar unit from U-haul...a metal clip that holds 4 way wiring connector was present and made it easier to support the unit. However, the unit I got from etrailer did not contain that clip. If this was a mistake, I would hope that clip is available.
Tyler M.
10/7/2020
Hi Chris, Thank you for your review. This wiring harness does not come with a mounting bracket. If you are looking to install one, I would recommend the Mounting Bracket 4-Pole Flat, product 18144. use the self tapping screws to attach it to the plastic bumper or the nuts and bolts to attach to the vehicle frame or metal bumper. If you do not want to screw into the bumper or frame, then I would recommend the 4-Flat Universal Mounting Bracket, product 118149. This one will come with zip ties that will secure the bracket to the hitch.
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Easy installation and perfect fit!
I picked the Curt trailer hitch over the etrailer hitch because it sticks out further past the bumper. I have the Thule T2 Pro XL bike rack and wanted to make sure I have enough clearance between the bike rack and the back of my 2020 Hyundai Santa Fe. Even though, your video shows enough clearance (1 1/2 inches ) with the etrailer hitch, with the Thule T2 Pro XL bike rack on the 2020 Santa Fe, I wanted more clearance. With the Curt hitch installed I have 3 inches between the closest point on the bike rack and the back of the SUV.
The installation was straightforward and easy. We did use a lift which made it much easier than the previous installation I did laying on the ground under our Honda CR-V. For that SUV I got the etrailer Hitch.
I followed the instruction video for the wiring harness, and it was a simple installation.
Perfect fit, very easy to install. I will go with e-trailer every time!
Easier than video of installation. Locate the cars wiring harness, unplug ; then open and plug up new product with one snap, and secure wire line along installed mounted support to flat surface and stick-on square box. Then continue securing wire line on other side of hitch and finally mount any excess wire to hitch while leaving short piece free to serve as connecting 4 post receptor. Over and done with. Thanks for being true to your easy promise
Bought this with this the etrailer brand hitch for my 2022 Hyundai Santa Fe Calligraphy. Easy plug and play install. Wiring harness package was missing when the hitch arrived as the box had popped open and it most likely fell out. Customer service had a replacement in the mail the very next day. Thank you!
Worked perfectly for my 2020 Santa Fe. Plug it in and route the harness to the hitch. Great product at a great price.
This trailer wiring kit was the exact match for the existing plug and play wiring underneath my 2020 Hyundai Palisade. However, you will need to order a separate bracket available at etrailer also to attach the trailer 4-pin connector plug to either the hitch or bumper fascia. I attached mine to the fascia pictured below.
I am so glad I came upon the Curt trailer hitch receiver. It's exactly what I was looking for because it actually has the crossbar tucked behind the bumper and all you can see is the receiver! And the T-One harness was easy to install and works great.
It all worked great, your installation videos were what made it possible for me to install the hitch and wire harness on my 2023 Hyundai Tuscon. The hitch fit perfectly the bolt holes lined up. The hitch was flush with the care frame there was not a MM of space between the hitch and car frame (see pic's) Note the hitch shipping box was damaged and had a hole in. But the wire harness did not fall out (see pic's)
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Jack
5/11/2025
Product is still functioning great after one year of being installed on my vehicle. I have had no issues with theses products.