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 # 118511
lowest price pledge
Our Price: $44.52
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.

Orders above $99 qualify for Free Shipping
Shipping Weight: 1.64 lbs
In Stock
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

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. Call 800-298-8924 to order Tekonsha custom fit vehicle wiring part number 118511 or order online at etrailer.com. Free expert support on all Tekonsha products. Guaranteed Lowest Price 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 (8)
  • Q & A (7)
  • Photos
  • Why etrailer?

Tekonsha Custom Fit Vehicle Wiring - 118511

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

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 in trunk
    • 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: 2.1 amps per circuit
    • Tail lights: 5.6 amps per circuit
  • 1-Year limited warranty


This custom-fit T-One connector plugs into your vehicle's wiring harness, which is located inside your trunk, behind the tail lights on both the driver's side and passenger's side. You will need to remove some interior trim or carpeting to access the 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 within 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.

118511 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details 118511 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 118511

Average Customer Rating:  4.8 out of 5 stars   (8 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.

- 118511

installed and functioned as advertised. 811687

- 118511
2013 Ford Focus

Great Hitches,Be it to tow a Trailer or just for a bike rack, Fast shipping, Best Prices and if it does not fit, easy returns too! 304851

- 118511
Nissan Versa

I have purchased one of these before for my versa, and it works fine, this one works fine too, but it takes more than an hour to install it. but I guess I am slow. but fine produce 233612

- 118511
2010 Subaru Legacy

Ordered on December 14 and with standard shipping it arrived on December 17th. Installation went well. The video on line was great and made the process easy. I would have given it a excellent rating if the cable ties, connectors, and in line fuse holder had been in the pack. These items were to be included but were not in the pack. 166152

- 118511

Delivery was very quick and appears to be the correct items. Waiting for warmer weather to install. 117819

- 118511

The installation contained no surprises. It went on "Without a hitch" so to speak. I would highly recommend it. 95642

- 118511
2011 Subaru Legacy

In all, I would say the product is good. After installed, it performs as advertised with no issues...Running the power line from the trunk to the engine bay was a real pain. Unless you need the extra power to the trailer, I would spend the extra couple of dollars and buy the kit that does not require the additional power. 35141

- 118511

Right on the money. Quick delivery too. 18726


Ask the Experts about this Tekonsha Custom Fit Vehicle Wiring

  • Trailer Wiring Harness for 2002 Subaru Legacy Special Edition Wagon
    For your Legacy Wagon, a plug and play option is not available. The trailer connector would need to be hard wired, using a universal kit like the # 119179KIT. The # 118511 harness you referenced wouldn't fit your vehicle. To install, the inputs on the taillight converter would need to be tapped into the existing tail light circuits. The easiest way to access the wiring harnesses that feed the tail lights would be to remove the tail light assemblies, like you would when replacing a bulb....
    view full answer...
  • Recommended Trailer Hitch for 2013 Subaru Legacy
    If you do not know what trailer you are going to be towing you can still get a hitch because the trailer will require a ball mount in order to tow. For your 2013 Subaru Legacy I recommend the Draw-Tite # 36493 because the use of stabilizing straps with accessories are not a manufacturer's requirement in order to maintain the warranty like they are with the Curt hitch. Also, please keep in mind that according to the owner's manual of your 2013 Subaru Legacy the maximum you can tow is...
    view full answer...
  • Recommended Trailer Hitch For 2011 Subaru Legacy
    We offer Class ll and Class lll trailer hitches for your 2011 Legacy. I recommend going with the Class lll because it gives you many more options when attaching any accessories like cargo carriers or bike racks. The trailer hitch I recommend is the Draw-Tite Max-Frame Trailer Hitch, part # 75673. This is a Class lll hitch and it has a 2-inch receiver opening. When installed, the distance from the center of the hitch pin hole to the back of the bumper is 4-1/2 inches. You will need to...
    view full answer...
  • What Is The Weight Of The Trailer Hitch That Fits 2015 Subaru Legacy
    The trailer hitch I recommend for your 2015 Subaru legacy is the Draw-Tite, part # 75673. This is a Class lll hitch and has a 2 inch receiver opening. The hitch itself weighs about 35 lbs. since we have not installed this on a 2015 Legacy I cannot tell you how much clearance you will have on your specific vehicle. it would depend on the vehicle suspension, tires, etc. We have installed this hitch on a 2011 Legacy and the clearance from the top of the hitch to the ground was 10 inches....
    view full answer...
  • Comparing Curt and Tow Ready Trailer Wiring Harnesses for a 2010 Subaru Legacy
    Normally when there is a choice between a powered converter and a non-powered converter I go with the powered converter. The reason is that the powered converter, in this case # 118511, gets most of the power for the trailer lights from the vehicle battery. This protects the vehicle wiring and any potential electrical problems that could occur should there be a short on the trailer wiring. Either harness will work for you but the little extra effort needed to route and connect the power...
    view full answer...
  • Trailer Hitch Installation for a 2014 Subaru Legacy
    The installation of the Draw-Tite # 75673 that you referenced that has been confirmed to fit your 2014 Subaru wouldn't be too difficult but I can understand wanting to have someone else install the hitch for you. However, check out the video link I attached to the right. It shows exactly how this hitch will install on a very similar Legacy as yours. Any qualified mechanic with a good reputation in your area would have no problem installing this hitch. Compared to what they normally do...
    view full answer...
  • Do Access Holes Have to be Drilled to Install a Trailer Hitch on a 2010 Subaru Legacy
    The top of the frame rails on the 2010 Subaru Legacy are covered and you cannot get them in from above. An access hole must be drilled on both sides like in the video I have linked. i have also linked the instructions for you. If you plan on doing some towing I recommend the etrailer ball mount kit # 989900. It comes with 2 ball mounts, 2 balls, a hitch pin with clip, and a carrying bag. For trailer wiring, use # 118511.
    view full answer...

  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality custom fit vehicle wiring for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate custom fit vehicle wiring information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Video Edited:
Joshua S
Test Fit:
Nicholas E
Updated by:
Laura H
Updated by:
Sarah W
Updated by:
Alexander C
Updated by:
Isabelle 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.