Arrives before Christmas To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.
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Quickly and easily install a 4-way trailer connector on your vehicle with this custom wiring harness. T-One connector plugs directly into existing wiring. Powered ModuLite reduces strain on wiring system.
Features:
Specs:
Installation
This custom-fit T-One connector plugs into your vehicle's wiring harness, which is located behind the driver's-side and passenger's-side tail lights. You will have to remove the tail light assemblies 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 and insert the provided fuse.
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 plugs 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. Note: 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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This wiring harness is relatively easy to install. Getting the power wire to the front of the car took a little thought and care, but not much time. I pushed the wire through the plastic protective under panel with a broom. It works great and fit my Kia Soul perfectly for a simple plug in assembly. It required no cutting and splicing of wires
Box came with a lot of tape, I assumed it’s been a returned harness. Everything was in the box except the instructions on how to wire it. I needed to search the internet to find something. I couldn’t find the one specifics to this harness but I think what I found will help make it work.
This was relatively easy to install and works wonderfully. With a transmission cooler the Soul is a great car for a U Haul that can hold a queen bed. This wiring harness made the conversion very easy. Running the hot wire was the only difficult part, but I was able to get it fully installed in about 45 minutes to an hour.
Not terribly difficult to install for me(not a mechanic). One thing that held me up was that I ran short by about 6 inches of wire to get to the connector on the passenger side lights(getting it high enough to reinstall the light fixture). Took a while to rerun the wires several times and then ended up moving the ground screw lower by about 5 inches. I ran the power black line along braking components and then fished it under the black cover that runs most of the way to the front and right up to the battery, I’ve never tied something to a car battery and it all worked out well. I used a 4 foot bamboo stake to run it both under the blastocyst shield in the bottom of the car and up to the battery. 6 inches of extra wire to get to the passenger side and I would have had this done in about 30 minutes.
Tips. A flat head screw driver will easily remove the plastic clips for extra room
I also used a flat head screwdriver wrapped in a paper towel to help the light fixtures out- there are 4 screws and 4 rubber push in pins on the outside- I put it between the light and car and gently popped it out.
Thank you I appreciate doing business with you.
Came in good time . Installed now and waiting for a road test
The product works. It connects like it should. Time will term if it will last. If anyone from etrailer was interested in a suggestion that has value, I recommend changing the wiring at the connecting ends for the tail lights. I recommend that the wire be fixed in an already bent shape to help us with successful installation. What this solves is when installing, we have to click those connectors into the tail lights and then the wire has to be bent to the side so that the tail light fits back in. That's chastising and can easily result in bad connections. But if the bend is done from the factory, that would help us.
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Kit was not manufactured for proper install. I had to cut harness wiring to the right rear light, and make it 14 inches longer. The extra wire that feed the power is also a joke. The whole design could of been better. The surge box should have been installed under the bumper. I tucked it in and tied it. Putting it a long with the ground behind the light is just plain stupid. (Limited Space) I believe Curt kit is superior but also could use a better design for install. This was a nightmare to deal with. And having to modify for install was poor manufacturing to save a dime.. I just hope when I test the system today; That it all functions as it should. I know I voided the warranty fixing their cheap build.
Sierra K.
11/10/2021
When you follow step 7 in the installation instructions, it mentions to either route the black power wire through a grommet along the exterior frame or follow the existing wiring along the thresholds into the engine compartment up to the battery, avoiding areas that may pinch or break the wire. By following the picture labeled C in the instructions, you should not have to add additional wire to make this kit work.
It works but unless you are a mechanic or have the ability to use a lift for the car it's not a quick job. It requires a lot of work to get it though the front fender. The driver side light cable should be longer to make it easier to be able to mount the transformer box. Currently mine is just sitting in my bumper unattached
Easy install… took about 10 minutes. No need to lower the exhaust
It was really easy to install! I only really had to run one wire from the battery to the rear of the car. The rest of the wiring was simple plug and play. A ground point was easy to find in the Kia Soul in the hatch back section directly below the hatch lock mechanism behind the interior panel. So no need to drill a hole.
It's a well made product. The reason for 4 stars instead of 5 is the instructions or really a lack of instructions. But as far as the product goes I give it a 5 star.
Will
12/22/2022
After a year I have probably used it a total of 20+ times and it has performed just as well as when we first installed it. No complaints at this point.
The product trailer hitch was a good fit for my Kia Soul. Running a wire to the front of the car proved difficult without having a lift, but the turn signal and brake lights are working.
Left side wiring needs to be about 6" longer to mount control box to body. However, it is installed and works properly. This is the 6th unit Ive installed since 2013.
The wire on the drivers side was about 2ft to short and had to add, ont the other side it was the right . You may want to look into this, other then the short wire it all went together pretty smooth.
Thomas T.
1/29/2021
Great
The wire on the left side is about 2 foot short the same as my 2020 Soul. With these new lights on the 2022 Soul there is no room to run them with out cutting wires. Some body need to try and install a wire harness on a real 2022 and make a video
Installed on my 2021 Kia Soul in half an hour, hardest part was snaking the ground wire from the rear to the battery.... car lamps came out easily, connectors snaked very easily & all fit great.
Worked out great and this particular wiring harness kept the car’s warranty intact.
Fairly easy to install, my only complaint would be that the wires are too short after mounting box.
Prefect fit, everything you need, easy wiring harness
Great quality
Everytime I order from etrailer, my orders come thru without no "hitches"... ;)
Perfect everytime!
I haven't had time to have it installed on my 2020 Kia soul. I will let you know more once this process has been completed. Looked it over and looks like just what I need. Will keep your site on my computer and use it for next purchase for my car;s electrical items.
Sorry about the delay in my review. Absolutely "no" complaints ! The entire project went quite well. Read the instructions, and the project went smoothly !
Installed this product and have traveled pulling a pop up camper. I haven't had any issues with this product. Has never let me down.
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Brooke M.
8/26/2025
If you're still needing instructions specifically for this kit, we have them available on our product page if you scroll down a little. You will see a link after all the product information :)