bing tracking image
  1. Custom Fit Vehicle Wiring
  2. Tekonsha
  3. 4 Flat
  4. Custom Fit
  5. Trailer Hitch Wiring
  6. Powered Converter
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
Tekonsha

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

Part Number: 118812
In Stock
ChristmasTree SantaHat Arrives before Christmas SantaHat ChristmasTree
$70.47
Retail:$130.38
You Save: 46%
Custom Fit Vehicle Wiring

Will this fit?

To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.

Add to cart
Custom Fit Vehicle Wiring 118812 - Powered Converter - Tekonsha
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

Customer Photos

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. 1-800-940-8924 to order Tekonsha custom fit vehicle wiring part number 118812 or order online at etrailer.com. Free expert support on all Tekonsha products. Great prices and Fastest Shipping for T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector. Custom Fit Vehicle Wiring reviews from real customers.
  • All Info
  • Reviews (69)
  • Q & A (0)
  • Photos

Tekonsha Custom Fit Vehicle Wiring - 118812

  • 4 Flat
  • Custom Fit
  • Trailer Hitch Wiring
  • Powered Converter
  • Tekonsha

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:

  • Provides a 4-way flat trailer connector at the back of your vehicle to power your trailer's signal lights
    • Compatible with 5-pole, 6-pole and 7-pole adapters (sold separately)
  • Connects quickly and easily
    • Locate connection points behind tail lights
    • Plug in T-connector
    • Run hot lead to car battery
  • Includes ModuLite to ensure that your vehicle's wiring matches that of your trailer
    • Powered module connects directly to battery to avoid overloading vehicle's electrical system
  • Constructed of 16-gauge bonded wire
  • Comes with dust cap for 4-way flat connector


Specs:

  • Maximum amperage:
    • Stop/turn lights: 5 amps per circuit
    • Tail lights: 7.5 amps per circuit
  • 1-Year limited warranty


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.


T-One Connection Location Points Behind Tail Lights

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 in the spare tire compartment.


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.


ModuLite Powered Tail Light Converter

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.



118812 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details 118812 Installation instructions

This Product Fits The Following Vehicles



California residents: click here


Customer Satisfaction Score:


Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 118812

Average Customer Rating:  4.8 out of 5 stars   (69 Customer Reviews)

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.

by:
2021 Hyundai Tucson

My package was on time, product works great. I would recommend Etrailer products. I would pack two sell dring screw in the package though.



by:
2020 Hyundai Tucson

perfect connectors took about 15 min to wire the whole vehicle fron start to finish from rear to front putting the wires so not to get tangled or interfere with anything that might cause problems down the road.



by:
2020 Hyundai Tucson

All in all very pleased with this product have it installed and working good. My only complaint is although very minor did not know you would have to heat connectors to hold together wiring so had to borrow a lighter. But really anyone can set this up just definitely need a ramp or something to lift your vehicle



by:
2020 Hyundai Tucson

Unbelievable service!!! Fantastic experience will shop this cite again!



by:
Hyundai Tucson

I got the Hitch installed on my Tucson in an hour. Took me another hour to route power cable for tail light harness. The harness was plug-n-go, very easy! I've had the hitch on my Tucson for a year now and I've used it. Towed a 5x8 enclosed trailer from NY to SC. Works fine for me since I got rid of my truck!

Mark profile picture

Mark

5/30/2022

Fantastic! Glad I installed it, without a truck at least I can go rent a trailer for $xx day.



by:

Instructions seemed a little generic. If the harness is for a specific vehicle, the instructions should be clear. Photos were a little dark, and didn't quite match what I had. I don't know if there was a model change they didn't adjust the instructions for.
Power wire needed to be a little longer. The instructions acknowledge this. Go buy a few feet of wire? Why didn't they include enough to begin with? How much more would 3 feet of wire added to the price of this module? I'm sure less than it cost me to buy it, let alone connectors, and gas and time to the store! I got it in and on, though. Worked when I tested it.



by:
2019 Hyundai Tucson

The unit worked well but cannot be installed as per instructions. The supplied plugs will NOT fit through the factory holes in the body. I had to cut the wires, install the plugs and and reattach them inside the rear fenders

Sierra K. profile picture
Etrailer Expert

Sierra K.

11/2/2021

As said in step 4 of the instructions, the grommet will need to be removed to fit the wiring harness through. If it already has existing wiring and cannot be removed, you may need to cut the grommet to allow the t-connector to pass through. You then would use silicone rubber to seal the grommet.



by:
2021 Hyundai Tucson

etrailer goes above and beyond costumer service, I always feel like i'm dealing with a friend. Curt hitches fit so perfect and the welds and paint are top notch. I fallowed your video on the wiring harness ,no problems, just dirty from crawling around under the car. A lift would have been nice. Thank you Julie H.



by:

I have been using the wiring harness for a year now with no trouble.

Jim profile picture

Jim

6/26/2022

Excellent



by:

This product was really easy to install. Fishing the power wire to the the hardest part and it was straightforward and covered well in the installation instructions. I love that I didn't have to splice into any wires.



by:

Took me a little longer than they said and I could have used a little more wire length to mount the box out of the way of the panel because of a factory mounted electrical unit behind the side panel but installation was fairly easy. Only thing is the tab “buttons “ holding the floor panel a couple broke but they can easily be replaced . The video helped



by:
2019 Hyundai Tucson

The kit has everything I needed. I did not realize this kit was made to be run inside the vehicle and the 4 pin plug and wiring would have to run from inside, across the bumper, to the trailer wiring. I was able to run it my way, outside the vehicle, without any problems. There is enough wiring, but not too much. Overall a good kit.



by:
2019 Hyundai Tucson

Overall it was a pretty easy installati on.

Bob H. profile picture

Bob H.

9/13/2021

great



by:
Hyundai Tucson

I bought a hitch and a wiring harness fo my Tucson. They have great products and delivery and keep in contact with you from the start. Everything I bought went together perfectly with no issues!!! I'll definitely buy from here again



by:

Maybe it was just me but the grommet that came zip tied on harness didn't seem to fit anything. No big worry just curiosity>



by:

Seems to be working as expected.

Carl profile picture

Carl

4/16/2023

Working just find without any problems.



by:

etrailer is the only place I will ever go to for hitches and wiring harnesses. Simply because they make it easy to add a trailer hitch to your car or truck. Everything fits as it says in the manual. Don’t waste your time with any competitors because you will be sorry you did.



by:

Amazing service amazing product. All of it was plug and play. I will buy from here again when i need more of anything they have



by:

Everything bolted up as it should. The trailer hitch fit perfect. Wiring harness for trailer towing also plugged in and worked perfect.



by:

Great product and easy to install. Works as advertised. Video on the site gives you step by step install directions



by:

We bought this kit because it came with a self-install video which was VERY helpful. The step by step directions are the best we’ve seen online. Even though it’s not the cheapest or most competitive in price, the extra couple or bucks was worth it for the installation directions. Shipping & customer service were also great.



by:

Peter profile picture

Peter

9/7/2023

Good, it’s invisible and just works.



by:

Great product, works great! Shipping was faster than expected.

Dena profile picture

Dena

3/2/2023

Its working out great!



by:
2020 Hyundai Tucson

Very easy to order, prompt shipment and I was constantly updated as to the delivery date.
I will definitely continue to do business with etrailer. This company provides great service.



by:
2021 Hyundai Tucson

the installation video was most helpful


25
69
Show More Reviews

See what our Experts say about this Tekonsha Custom Fit Vehicle Wiring

  • How Can I Tell If My Trailer Module Needs To Be Replaced
    It certainly sounds like you are in need of a new module. It is not unheard of for them to go bad. Generally when it works fine for a long period of time, then stops working, this is a sure sign that it needs to be replaced. We would want to verify that the new fuse you used is a 10 amp, and that you are 100% sure that you have a good ground free of any rust, paint or corrosion. Other than that, there is really nothing else that could cause this issue. The module is wired directly to...
    view full answer...
  • Recommended Wiring Harness for a 2019 Hyundai Tucson
    No, sorry the Curt item # C89KR is set up completely different then the Tekonsha item # 118812 wiring harness. Besides the length of the wires being different Tekonsha won't honor their warranty if you don't follow the installation instructions. I recommend the Curt item # C89KR because of their converters being more reliable and their installation method being better. Both of these harnesses are confirmed to fit the 2019 Hyundai Tucson. I have linked both installation instructions...
    view full answer...
  • Wireless Harness Trailer Connector Compatible With 2021 Hyundai Tucson
    The T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118812 is confirmed by Tekonsha to fit your 2021 Hyundai Tucson Ultimate. I've attached the installation details and it will install in the same way as the previous model years.
    view full answer...
  • Trailer Hitch and Towing Equipment Recommendation for 2019 Hyundai Tucson
    For your 2019 Hyundai Tucson, I'd recommend the Curt Class III, part # C13240 which fits all models except for the Night Edition with the dual exhaust tips on both sides of the vehicle. If you do have the Night Edition, unfortunately the exhaust would interfere with the installation of a hitch and we don't offer anything that would work. For a trailer wiring harness, I'd recommend the Tekonsha # 118812, for a ball mount use # 2753 and # 19260 for a 1-7/8 or # 63845 for a 2 inch ball. I've...
    view full answer...
  • Parts Needed To Install 7-Way and Tekonsha Primus IQ Brake Controller On 2019 Hyundai Tucson
    As the T-One Vehicle Wiring Harness # 118812 is only a 4-way flat connector you will need the Universal Installation Kit for Trailer Brake Controller # ETBC7 as well for your 2019 Hyundai Tucson. This installation kit will accept the 4-way from the Tekonsha harness for the lighting and provide you with the wiring needed to install the Tekonsha Primus IQ Trailer Brake Controller # TK90160.
    view full answer...
  • Can T-One Connector 118812 Be Wired To Existing 12v Outlet On 2021 Hyundai Tuscon?
    To install the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118812 you were looking at on your 2021 Hyundai Tuscon you will need to route the power wire up to the positive terminal of your battery with the included fuse. These harness are tested with a dedicated circuit, and wiring it into an existing circuit can overload that circuit whenever the outlet is used and damage the modu-lite box which would not be covered by the warranty. I included a video of...
    view full answer...
  • Why Does the Trailer Wiring Harness For a 2019 Hyundai Tucson Require a Power Wire
    The T-One Vehicle Wiring Harness part # 118812 which is a fit for a 2019 Hyundai Tucson does require a wire to be run to the vehicle's battery for power. The reason for this is because the vehicle's tail light circuits are not rated high enough for the additional amp draw of the trailer lights. Furthermore, this acts as a barrier to protect the vehicle' tail lights if there were ever an issue with the trailer's lights. In regards to other trailer wiring harnesses that don't require a power...
    view full answer...
  • Parts Needed For Installing a 7-Way Blade Trailer Connection On a 2022 Hyundai Tucson
    Currently there is not a T-one wiring harness for your 2022 Hyundai Tucson that will be wired directly to a 7-way trailer connector. You will need to use the Tekonsha T-One Vehicle Wiring Harness # 118812 to connect to a 7-way like the one included in our Universal Installation Kit # ETBC7. If you wish to not have the quick disconnect you can cut off the connectors and use Deka Heat Shrink Butt Connectors # DW05744-5 to have a permanent connection. The universal kit includes all the wiring...
    view full answer...
  • Tools Needed To Install Trailer Hitch Receiver and Wiring Harness On a 2019 Hyundai Tucson
    For your 2019 Hyundai Tucson the Draw-Tite Max-Frame Trailer Hitch Receiver # 75836 includes the receiver, 7 mounting bolts and 7 washers needed to install the receiver on your Tucson. You will need the following tools to install this receiver. A 16mm socket, ratchet wrench, torque wrench capable of at least 42ft-lbs torque and a flat head screw driver. Safety glasses are recommended to protect your eyes from any foreign objects that may drop off the frame. The Tekonsha T-One Vehicle...
    view full answer...
  • Class III 2 Trailer Hitch Receivers Available For A 2022 Hyundai Tuscon
    There are 2 Receivers that are available for you 2022 Hyundai Tucson Hybrid. Both receivers are 2" class III receivers and are rated for a maximum of 525lbs of tongue weight and a trailer weight of up to 3,500lbs. The Draw-Tite Max-Frame Trailer Hitch Receiver # DT22MR will have a slightly more visible cross tube but will include a mounting tab for the trailer wiring. I recommend the Curt Trailer Hitch Receiver # C94WR as the cross tube will be less visible. It does not have a tab for...
    view full answer...
  • Will Trailer Hitch Fit 2020 Hyundai Tucson Sport for Towing
    The only Hyundai Tucson model that the trailer hitches won't fit is the Night Edition with the dual exhaust tips. As long as your 2020 Hyundai Tucson Sport isn't that edition then you're good to go! Out of the available hitches it's always better to go with the larger 2" hitch receiver (for fitment with more accessories) which we have both the Draw-Tite # 75836 and the Curt # C13240. I personally like the Curt design more because the safety chain loops are parallel to the ground as opposed...
    view full answer...
  • 2019 Hyundai Tucson Ultimate Trailer Wiring Harness Recommendation
    We have just what you are looking for with the Tekonsha trailer wiring harness part # 118812 as this is a plug and play harness that requires only you to run the power wire up to the vehicle battery. The converter box of this kit is the most reliable option for your vehicle which is why I recommend it over other similar options.
    view full answer...
  • Trailer Wiring Harness Recommendation for 2021 Hyundai Tucson with LED Taillights
    The Curt trailer wiring harness part # C89KR is a fit for your 2021 Hyundai Tucson with LED taillights but I would actually recommend the Tekonsha part # 118812 as it has a more reliable converter box.
    view full answer...
  • Testing a Malfunctioning Wiring Harness on a 2021 Hyundai Tucson
    This can be caused by a few things. First and foremost, you will need to check to make sure your ground is secure and attached to bare metal. It is best to not have this stacked with other wires and should be its own ground source. Once this is done, you will need to check your 4 Flat connection using a tester, like the Circuit Tester # PTW2993. The green wire is for the right turn signal, the yellow is for the left turn signal, and the brown wire is the brake signal, the one you are having...
    view full answer...
  • Troubleshooting Driver Taillight On 2019 Hyundai Tucson Not Working W/ Tekonsha 118812 Installed
    I am sorry to hear about your issue! To find out what is causing the driver side tail light of your 2019 Hyundai Tucson to not work with the Tekonsha # 118812 installed you will need to remove your driver side tail light and check that the connector going into your factory connector and the connector going into the tail light are fully seated. If one is loose go ahead and check your lights again. Next remove the connectors and look for any debris or bent pins inside the connectors that...
    view full answer...

Do you have a question about this Custom Fit Vehicle Wiring?


Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Jameson C
Expert Research:
Jameson C
Employee Dustin K
Video by:
Dustin K
Employee Chris R
Video Edited:
Chris R
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Written by:
Alexander C
Employee Bradley B
Test Fit:
Bradley B

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.


Product Experts Available Now!
Call 1-800-940-8924