bing tracking image
  1. Custom Fit Vehicle Wiring
  2. Tekonsha
  3. Custom Fit
  4. Trailer Hitch Wiring
  5. 4 Flat
  6. Powered Converter
T-One Connector Assembly w/Upgraded Circuit Protected ModuLite HD Module

T-One Connector Assembly w/Upgraded Circuit Protected ModuLite HD Module

Item # 118671
Our Price: $50.99
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.

This item qualifies for Free Shipping
Shipping Weight: 1.63 lbs
In Stock
T-One Connector Assembly w/Upgraded Circuit Protected ModuLite HD Module Powered Converter 118671
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

Need help with installation?
Locate installers near me
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. 1-800-496-5010 to order Tekonsha custom fit vehicle wiring part number 118671 or order online at Free expert support on all Tekonsha products. Great prices and Fastest Shipping for T-One Connector Assembly w/Upgraded Circuit Protected ModuLite HD Module. Custom Fit Vehicle Wiring reviews from real customers.
  • All Info
  • Reviews (19)
  • Q & A (0)
  • Photos
  • Why etrailer?

Tekonsha Custom Fit Vehicle Wiring - 118671

  • 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 in rear cargo area
    • Plug in T-connector
    • Run hot lead to car battery
  • Includes ModuLite power converter to ensure that your vehicle's wiring matches that of your trailer
    • Powered module connects 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: 4.2 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 in your rear cargo area on both the driver's side and the passenger's side. 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 your rear cargo area.

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.

118671 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details 118671 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Satisfaction Score:

Customer Reviews

T-One Connector Assembly w/Upgraded Circuit Protected ModuLite HD Module - 118671

Average Customer Rating:  4.8 out of 5 stars   (19 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.


I think this is a nice option for cars that don’t have factory trailer connection hidden in the trunk. This is no insult to the product but I’m very surprised that many of the DIY videos and I even the instructions suggest running the power wire outside of the car. It’s pretty easy to pop the door threshold and tuck the wire under the carpet inside. If you purchase an add a circuit harness you can usually run it right to your fuse box nice and neat. Either way the product is great, definitely better than cutting into factory harness.


The wiring harness sure makes it easy to wire up the trailer lights. The video instructions were very helpful, too.

2017 Subaru Legacy

Still works flawlessly after a year on a 2017 Subaru Legacy Sport.


Wow a company that does what they say they’re going to do. The staff was very very helpful guarantee me I would receive my part on the time that I needed it for a trip. Highly recommend this website and team

2016 Subaru Legacy

It's been a year since I purchased a custom fit wiring harness and tow hitch for my new 2016 Subaru Legacy. I found the installation of both easy and encountered no issues at all. I did choose to simply keep the wiring harness stored inside the trunk and simply let the trunk seal around the flat wire ribbon when in use so that I did not need to compromise the water tight chassis of my new car.

Both the hitch and harness have worked perfectly and have faced ample use.

These are not the first of each as I've purchased. I also bought a roof rack and hitch mounted bike rack from etrailer.

I have been thrilled with each purchase and will most definitely return to etrailer as I already have multiple times. Good quality, great prices and fantastic customer service with rapid response to product questions.


Works perfect, but don't let your installer take any shortcuts! Mine tapped into a hot wire in the back rather than run a wire all the way to the battery (unbeknownst to me) and that had me troubleshooting my trailer lights for hours! All was fine with the trailer once the correct car wiring was completed as directed. I am very impressed with the web site, products, and installation support of etrailer. These folks do a great job, even as far as waiting a year for a review solicitation.

2017 Subaru Legacy

This is my 4th purchase through etrailer with all four being flawless. Fast shipping, good products at reasonable prices. I had my vehicle prepped prior to hitch arrival and took me less than 1 hour to install these hitches and wiring harnesses. Instructions are so easy a caveman could install. All four dealings with etrailer are 5 stars and will continue to use them after future vehicle purchases.

2016 Subaru Legacy

Running the hot wire to the battery is a pain in the rear, other than that it works well. I ran it out through holes in frame rails on trunk floor and side on passenger side to stay away from muffler. Only hole I drilled was for ground.

Still working fine for a year on my 2016 Legacy.
Dennis - 06/25/2019

2016 Subaru Legacy

Hitch and wiring fit perfectly. I only trust ETrailer for such matters. Installation videos, and great customer service. Thank you. I am a long term multiple item buyer.

2019 Subaru Legacy

Product arrived safely as advertised. Haven't installed yet but looks to be pretty straight forward!


Everything was great
Best part of the
experience was being able to talk to a live person (Natalie A) helped me order what I needed!
Available, Knowledgeable, and courteous other companies should take lessons.
It is the reason will be the first place I look and recommend.


Product was easy to install and works very well. Would recommend to anyone needing a reliable Subaru trailer light connection


etrailer is great. Order was shipped the same day And I received package ahead of schedule. Also, etrailer had a video installation guide for my vehicle that helped things go smoothly.


Easy to install nice works great


Easy to order and was shipped fast. Sales and service are excellent. Price included shipping and was the best price found.

2019 Subaru Legacy


The harness fit fine!

2017 Subaru Legacy



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

  • Trailer Hitch and Wiring for a 2016 Subaru Legacy
    For your 2016 Subaru Legacy a popular hitch option is Draw-Tite Class III trailer hitch # 75673. This hitch has a 2 inch receiver and is rated for 600 pounds tongue weight and 4,000 pounds gross trailer weight. Consult the vehicle owner's manual for the towing capacity of the vehicle and go by the lower of the 2 ratings. I have linked a video showing an example installation for you. For trailer wiring you can use Tow Ready harness # 118671. This connector plugs in line with the vehicle...
    view full answer...
  • Trailer Hitch, Wiring, and Accessories for a 2016 Subaru Legacy
    I will be happy to help you out. For a trailer hitch for your 2016 Subaru Legacy I recommend Draw-Tite trailer hitch # 75673. This hitch is rated for 600 pounds tongue weight and 4,000 pounds gross trailer weight. Be sure to check the vehicle owner's manual to see what your Legacy is rated for and go by the lower capacity. I have linked a video showing an example installation for you. For trailer lights I recommend Tow Ready 4-Way flat # 118671. Tow Ready harnesses have a good reputation...
    view full answer...
  • Trailer Hitch Recommendation for a 2016 Subaru Legacy
    The Draw-Tite part # 75673 would fit and work well on your 2016 Subaru Legacy so I would recommend it for you. If you wanted to do some towing you might be interested in etrailer ball mount kit # 989900. It comes with 2 ball mounts; one with a 3/4 inch rise or 2 inch drop and one with a 2-3/4 inch rise or 4 inch drop. It also includes a 1-7/8 inch ball, 2 inch ball, hitch pin with clip, and a storage bag. If the ball mount kit does not include a ball mount with the right rise or drop...
    view full answer...
  • 2015 Subaru Legacy 2.5 Trailer Hitch Recommendation for Towing Small Trailer
    We can definitely help point you in the right direction to pick out all of the correct components to tow a trailer with your 2015 Subaru Legacy. The first thing you'll want is a trailer hitch which for that I recommend the Draw Tite part # 75673 which is a custom fit Class III hitch with a 2 inch opening. This means it has plenty of capacity and was designed to specifically fit your vehicle. I attached an install video for this hitch for you to check out as well. For trailer wiring the...
    view full answer...
    Image 1 for
  • Installation Instructions for EcoHitch 306-X7271 for Subaru Legacy
    Congrats on your purchase! We typically include a link to the installation instructions in each hitch product page but since EcoHitch does not provide a link to the installation instructions on their website, we're not able to provide one on ours. Your EcoHitch # 306-X7271 (confirmed to fit all models of the 2015 Subaru Legacy) will definitely include a hard copy of the complete installation instructions but I have attached snips of the written portion of the digital instructions. That...
    view full answer...
    Image 1 for Image 2 for
  • Does Curt Trailer Hitch Fit 2016 Subaru Legacy 3.6R Limited
    I checked with Curt for you and am happy to confirm that yes, the Curt Trailer Hitch # 13390 is a fit for your 2016 Subaru Legacy 3.6R Limited! This is a Class III hitch with a 2" receiver, 4,000 lb towing capacity and robust 600 lb tongue weight capacity; it is made in the USA and comes with a lifetime warranty, which speaks to its durability. If you are going to be towing you will need a wiring harness to power your trailer's lights, the T-One Connector Assembly w/Upgraded Circuit Protected...
    view full answer...
  • Recommended Trailer Hitch and Wiring for 2016 Subaru Legacy
    For your 2016 Subaru Legacy Sedan, I recommend going with a Class III trailer hitch. While you may not ever need the higher rated weight capacity of a Class III hitch, the 2 inch receiver opening will allow you to choose from many more hitch-mounted accessories such as bike racks and cargo carriers than that of a 1-1/4 inch receiver on a Class II hitch. I recommend the Draw-Tite Class III Max Frame Receiver Hitch # 75673 for a couple of reasons. First, when compared to the Curt Class...
    view full answer...
  • Recommended Trailer Hitch Receiver for 2018 Subaru Legacy
    Your 2018 Subaru Legacy is rated to tow 1,000lbs. I recommend the EcoHitch Hidden Trailer Hitch Receiver # 306-X7384 as it will not have the exposed cross tube and gives you a 2" receiver that will allow for more hitch accessory options. For the trailer lighting you will need the Tekonsha T-One Connector Assembly # 118671. This will give you a 4-way flat connection to control the lights on your trailer. Our etrailer Ball Mount Kit # 989900 will give you 2 different ball mounts that...
    view full answer...
  • 4-Pole Trailer Wiring Harness for 2016 Subaru Legacy
    There is no issue installing a 4-pole trailer wiring harness like # 118671 or # C56246 on your 2016 Legacy that has the Subaru EyeSight collision avoidance system. Lots of our Subaru-owner customers have done so. Between these two items I recommend the Tekonsha # 118671, which is shown in the linked installation video, since we have found their harnesses to be very reliable. The Eyesight system is based around several cameras that monitor road conditions and generate warnings. The wiring...
    view full answer...
  • Best Hitch Receiver for Towing a Jet Ski w/ a 2017 Subaru Legacy
    I would be happy to help you! The best hitch for your 2017 Subaru Legacy is going to be the Draw-Tite Max-Frame Trailer Hitch Receiver item # 75673. This hitch is custom fit and bolts directly to your Legacy with included hardware. This hitch has the highest capacity for both towing weight 4,000 lbs and tongue weight 600 lbs out of the available hitches for your car. You will want to verify what your Subaru's towing capacity is and go off of that number. You should have no problem towing...
    view full answer...
  • Trailer Hitch for 2016 Subaru Legacy With the Most Ground Clearance
    You're right on the money; the trailer hitch receiver with the most ground clearance for your 2016 Subaru Legacy is the EcoHitch Hidden Trailer Hitch Receiver # 306-X7271. The reason why is how it installs, with the hitch being completely hidden which means the receiver is going to be up higher near the bumper than other hitches. I have added a photo of this hitch installed, compared to the Draw-Tite Trailer Hitch # 75673 and Curt Trailer Hitch # 13390 so you can see the difference. Since...
    view full answer...
    Image 1 for
  • What 2" Hitch do You Recommend for My 2019 Subaru Legacy?
    For your 2019 Subaru Legacy, I recommend the etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2" # e99YR. This hitch comes with the easiest installation process out of any hitch we carry for your vehicle. It only takes about 1 hour and includes all of the mounting hardware required for installation. If you plan to use non-trailer loads such as bike racks or cargo carriers, you need to use stabilizing straps # 18050 with those accessories. If you do plan on...
    view full answer...

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

  • Why

    At we guarantee:
  • 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:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jacob T
Video Edited:
Jacob T
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Isabelle B
Updated by:
Isabelle B
Employee Cole B
Installed by:
Cole B
Employee Chris R
Video by:
Chris R
Employee Alexander C
Written by:
Alexander C
Employee Brent H
Test Fit:
Brent H

At 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.