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

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

Item # 118686
Our Price: $63.83
You Save: 47%
Custom Fit Vehicle Wiring

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Custom Fit Vehicle Wiring 118686 - Powered Converter - Tekonsha
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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. 1-800-940-8924 to order Tekonsha custom fit vehicle wiring part number 118686 or order online at 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.
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  • Reviews (11)
  • Q & A (0)
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  • Why etrailer?

Tekonsha Custom Fit Vehicle Wiring - 118686

  • Custom Fit
  • Trailer Hitch Wiring
  • 4 Flat
  • 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.


  • 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


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


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.

Tail light diagram

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 connector will be stowed in your trunk.

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.

118686 Tekonsha T-1 T-Connector - 4 Wire - Modu-Lite Converter Included

Installation Details 118686 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 - 118686

Average Customer Rating:  4.5 out of 5 stars   (11 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.

2019 Honda Civic

The running lights power wire quit working after 3 months. Somewhere in the power module something broke or burned out. So I had to buy a whole new harness.

I will have our customer service team reach out to you. The harness does have a one year warranty.
-- Etrailer Expert Jenny N - 01/31/2022


Everything you need all in one kit. Running the wires through the car's raceways is a pain in the butt, but that's the cars fault. End result is a professional install. Great product!

2017 Honda Civic

Great product ..I used this to add lights to the lower part of my civics rear bumper. I did not want to cut wires and the factory clips work great and the added benefit that I am isolating the power form the cars wireing system is great .

Michael - 10/23/2020

2017 Honda Civic

I bought my Tekonsha 118686 trailer wiring kit shortly after I bought my 2017 Civic. I emailed the company about fitment before purchasing and they got back to me promptly and reassured my worries. (Curt only had a hack and splice kit at the time)
This kit is great, no need to splice wires into the factory wires, all plug and play, the only wire needed to crimp is the main power wire which attaches to the battery and sends power to the harness pack.
Most of the instillation was a breeze, I cut a slit into the grommets so the wires are nestled in nice with the factory taillight wires.
The only tricky part was running the power wire, I wanted it to be completely out of sight, so I tucked it auto conduit and hid it up in the wheel arches, and the ground effects.
I'm sure there could have been a faster route, but I'm a perfectionist.
The kit works flawlessly and I couldn't be happier !!! is amazing. I don't know how they do it, but they simply are the best, knowledgeable staff, and competitive prices make this business a pleasure to deal with.
A+ in my book


the first wiring harness I got was the wrong one. It was for a coupe instead of a sedan. I went back and looked at my order. You really had to look close at rhe sight to see it was for a coupe. Called for a return authorization which was given with no problem. Had to pay for return shipping which was nearly three times as much than to ship it to me initially. Rachel was very helpful in making sure I got the proper harness. It installed easily and worked the first time. will order again should the need present itself.


Very easy to get it hooked up great pr oduct

James - 11/15/2021

2006 Honda CR-V

Never used it. Sold the car because of pandemic prices

2017 Honda Civic

quality product. well written, easy to understand installation instructions.

2017 Honda Civic

Always the best service, thanks.


Awesome quality, extremely fast shipping and good directions

2019 Toyota Corolla

arrived on time...installed with no problems.....I cut the metal like instructed, but have no reason why !!!


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

  • Trailer Wiring Harness to Power Lighted Hitch Cover on a 2017 Honda Civic Sedan
    You certainly use hitch light # CR-017 on your 2017 Honda Civic sedan with Curt trailer hitch. You can use the light by installing trailer wiring harness # 118686. Once installed the hitch light will plug into the harness 4-Way which will power it. It will help to make your Civic more visible in the fog. Distance from the center of the hitch pin hole to the back of the light housing is 2 inches minimum, 3 inches maximum (less if using the foam gasket).
    view full answer...
  • Recommended Trailer Wiring Harness For 2016 Honda Civic Sedan
    We do have a wiring kit that will work with your 2016 Civic but they require hardwiring the harness on your vehicle. Curt T-Connector Vehicle Wiring Harness, part # C56011 is not a confirmed fit for your 2016 Civic. The harness I recommend for your Civic is the Tekonsha # 118686.
    view full answer...
  • Trailer Wiring Harness for a 2018 Honda Civic Hatchback
    Trailer wiring harness # 118686 is not confirmed to fit the hatchback models of the 2018 Honda Civic. There are only hardwire options available. Of the available hardwire options I recommend # 119147KIT because we hear about fewer issues with the Tekonsha brand.
    view full answer...
  • Trailer Wiring Harness Recommendation for 2020 Honda Civic Hatchback
    The Tekonsha # 118686 you'd mentioned fits the Civic sedan only. For the hatchback, you'll need to use a splice-in kit like part # 119147KIT. I've linked to a product video where our install tech Dave will run you through a typical install.
    view full answer...
  • Trailer Hitch, Wiring and Ball Mount Recommendation for 2016 Honda Civic Sedan
    For your 2016 Honda Civic sedan the recommended trailer wiring harness is the Tekonsha kit part # 118686 which is a confirmed custom fit. This brand of wiring kit is the most reliable so it is hands down the best option. Now with Class I hitches like the Draw Tite part # 24954 that you referenced you have to go with the ball mount the manufacturer recommends. So that means you'd need the # 3593 that you refernced. Then for hitch balls you'd want part # 19256 for a 1-7/8 inch ball or part...
    view full answer...
  • Fascia Trimming Needed to Install Trailer Hitch Receiver on 2019 Honda Civic Sedan
    I can certainly understand the hesitation of having to trim the fascia to install a trailer hitch in your 2019 Honda Civic sedan, but that's the only way to get a hitch installed because the only hitch that fits this vehicle is the Draw-Tite Trailer Hitch Receiver # 24954. Hitches are designed to fit specific years, makes and models of vehicles which is why the Draw-Tite is the only hitch you can use. The fascia trimming is minor though, just a 2-1/2" x 4" cut out, and it won't be visible...
    view full answer...
    Image 1 for
  • Will a Draw-Tite Hitch # 75174 Work on a Cadillac SRX AWD
    As long as your Cadillac SRX AWD is between the years of 2004-2009 and it does not have the Sport Package fascia this Draw-Tite Max-Frame Trailer Hitch Receiver # 75174 would work for your vehicle. I attached installation instructions and an installation video of this product for you to check out also. To complete your towing setup you may be interested in the following products: Tekonsha Wiring Harness # 118686 Ball Mount 3/4 inch Rise or 2 inch Drop # 2923 Hitch Ball with 2 inch Diameter...
    view full answer...
  • Trailer Hitch That Fits a 2018 Honda Civic Sedan
    There is a trailer hitch that will fit a 2018 Honda Civic sedan but the Curt Trailer Hitch Receiver # C11463 will only fit a '18 Honda Civic hatchback (excluding those with a center exhaust). Instead you will want to use the the Draw-Tite Sportframe # 24954, which will fit a 2018 Civic sedan (excluding those with a center exhaust); the correct drawbar for this hitch is the Draw-Tite # 3593 which does come with a pin and clip; you will need 1-7/8" Hitch Ball # 19256 or 2" Hitch Ball # 19258...
    view full answer...
  • How to Transport Motorcycle with 2017 Honda Civic
    The Draw-Tite Class I Sport Frame Receiver Hitch # 24954 referenced in your question is confirmed to fit your 2017 Honda Accord if it is the sedan or hatchback, and it does not feature the center exhaust. This Class I hitch has a 1-1/4 inch opening and a tongue weight capacity of 200 pounds. We do have some motorcycle carriers available, however they are all designed to fit into higher-rated, 2 inch hitch receivers. Most likely, the combined weight of a motorcycle carrier and motorcycle...
    view full answer...
  • Trailer Hitch and Wiring for a 2016 Honda Civic EX Sedan
    Drilling is required to install Curt trailer hitch # C11604 but there is no trimming mentioned. I have linked the instructions for you. You can install the hitch without having the vehicle on a lift. If you have ramps or some jack stands then those will provide you will more space to work. The recommended ball mount for this hitch is # C45521. For a 1-7/8 inch ball I recommend # 19256 and for a 2 inch ball I recommend # 19258. And for trailer wiring I recommend # 118686 to add a 4-Way...
    view full answer...
  • Trailer Hitch Recommendation for 2016 Honda Civic and Why Can It Only Carry 2 Bikes Max
    For your 2016 Honda Civic there are only Class I hitches available. And since they have lower capacities you can only carry up to two bikes. If you try to carry more you will damage the vehicle most likely. I had a customer come back and try to carry 3 bikes on a Class I hitch and he said the frame of his vehicle was bending and cracking. The Draw Tite part # 24954 would be the hitch for you to use as it does not require the stabilizer strap like the Curt does. I attached a picture that...
    view full answer...
    Image 1 for
  • Parts Needed To Tow a Trailer and Haul a Cargo Carrier With a 2016 Honda Civic Sedan
    Currently, a class I receiver like the Curt # C11604 that is rated for 200lbs of tongue weight and towing up to 2,000lbs is the only receiver available for your 2016 Honda Civic Sedan. There is not a receiver capable of supporting the weight of your Curt carrier fully loaded behind your Civic and this is most likely due to the structure under your Civic not being able to support the weight. The 19x47 Curt Cargo Carrier # C18110 will fit the class I receiver for your Civic. You will only...
    view full answer...
  • Recommendation for Towing Dirt Bike with 2016 Honda Civic
    To tow a dirt bike with a 2016 Honda Civic, you will need to use a trailer because there isn't a hitch receiver and motorcycle carrier compatible with your vehicle. I recommend using the Curt Trailer Hitch Receiver - Custom Fit - Class I - 1-1/4" # C11604 as well as the Curt ball mount # C45521 and hitch ball # A-82. You will also need the pin and clip # F-4 and wiring harness # 118686. I've attached some videos to assist. If you need a trailer, I recommend the Detail K2 Mighty Multi...
    view full answer...
  • Parts Needed For Trailer Towing With a 2016 Honda Civic Sedan
    In looking at your owners manual for your 2016 Honda Civic it is a bit confusing on its trailer towing ability. It does mention that trailer towing will void your warranties but it also lists including trailer tongue weight into your maximum cargo weight rating. If you feel that you want to tow with your Civic I recommend the Curt Trailer Hitch Receiver # C11604 as it is the easiest to install. You will not have to remove your rear bumper and fascia to install this receiver. The hitch...
    view full answer...

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Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Michael H
Expert Research:
Michael H
Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Wilson B
Updated by:
Wilson B
Employee Isabelle B
Updated by:
Isabelle B
Employee Alexander C
Written by:
Alexander C

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