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 Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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

Item # 118549
Our Price: $70.35
You Save: 38%
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: 1.78 lbs
In Stock
Tekonsha Trailer Hitch Wiring - 118549
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

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. 1-833-496-1390 to order Tekonsha custom fit vehicle wiring part number 118549 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.
  • All Info
  • Reviews (52)
  • Q & A (0)
  • Photos
  • Why etrailer?

Tekonsha Custom Fit Vehicle Wiring - 118549

  • 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: 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 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 within your trunk or 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.

118549 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details 118549 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 - 118549

Average Customer Rating:  4.6 out of 5 stars   (52 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.

2014 Ford Focus

Great products that fit properly. The instructional videos are great. We installed a Draw Tite tow hitch and trailer light hookup on our 2014 Ford Focus. Everything fit properly, and went together just like the video showed. No surprises.


great wireing harness


Actually yeah man.. thinks working great. I've used it at least 20 times in the last year from towing a small trailer for my canoe or my luggage carrier hitch where I wired brake lights on it. Thanks ill leave feed back for sure. Lutterally used it yesterday.


The video was exactly how the install went - no surprises. I thought the harness was well made and not something that would wear out in a couple months. The price was cheaper than other places with "generic" harnesses.

2012 Ford Focus

This must be the fifth or sixth time I have ordered from etrailer and have not been disappointed. One of the best things about etrailer has to be the installation videos. Before my son and I started we watched the hitch and wiring installation videos and even took my tablet to the garage as a reference. Pricing and delivery are more than competitive and because of the support I prefer to give them my business.

Everything is working just fine and my son has towed his little trailercarrying his dual sport motorcycle hundreds of miles without a problem. Verysatisfied with our purchase and impressed that etrailer is dedicated to thecustomer experience. Thanks
Spence J - 04/11/2016

2013 Ford Focus

I installed a trailer hitch on my 2013 Ford Focus so that I could pull my two kayaks on a small trailer. There are two ways to install trailer lighting, either buy a basic harness and splice in the factory harness or you can buy this product and plug and play. I am not excited about tearing in the factory harness as there is no way to go back to the original if you have to or choose to. The way this harness is designed if at some point you decide to remove the wire harness it can be done easily. The installation is pretty easy, the video is very helpful as the instructions are not very clear. The only problem that I experienced is that during the installation you have to cut through the grommets behind each tail light and the connectors are pretty large so it is a little tough pushing the connectors through the grommets. I would recommend that when you add the ground that you remove the paint for the body panel. It might work at first if you don't but over time the ground will stop working and you will be frustrated as to why your trailer lights don't work. One other alteration I made is I wired my power inside the car, I am not saying that the video is wrong, there are more than one way to get the power from the battery to the harness; however, I was not wildly crazy about running power under my car so instead I ran it inside, just my preference. There is a grommet right behind the glove box that you can get through pretty easy, there are video's on youtube to pull power for an amp to the battery .

Ford Edge

Only complaint is that the instructions for a slit in the taillight grommets didn't work that well. The plugs were to big to squeeze through without ripping tho holes even bigger. It would have been easier and keep a better seal if you cut the grommet from the edge to the wires. I did this to run the trailer plug to the mount on the hitch. It isn't ripped and the grommet seals pretty well.


Got here early, easy install, I followed everyone else's advise and used a fuse tap instead of running it to the battery, lights work flawlessly.


The wiring harness was super easy to install. No splicing needed. Pop out a panel, pull a tail light out, plug it in, put it back together. Works great!

2013 Ford Focus

It's a new 2013 Ford Focus and I was not in any rush.
The wiring took me about 3½ hours, start to finish. I ran the wire inside the car and had trouble finding a place to exit the firewall so I exited the floor under the clutch, through a grommet and up the firewall to the battery. You need the 12 volts to run the 4 prong trailer plug.
Works great


Nothing but great as for a review for the team at etrailer. There was a slight problem with the delivery, but it was quickly resolved by their team and I had everything delivered far sooner than I had expected. The installation was a snap and I was impressed with the system they provided to fish the bolts thru the frame. My first thought was "yea, sure" when I saw what was in the package, "this ain't going to work". I was wrong, it worked like a charm. I have designed tooling for the Air force. and this deserves an award for it's simplicity.

2013 Ford Focus

You knew the order was here before I did!
Install went well. The video was right on. I was surprised by how dirty everything was inside. Cleaning took a lot of extra time. I made a few miscues that the video made to look easy. Practice and a clean area makes perfect.
Works great! Thank You. I will recommend your products in future.

Ive used it several times and its working out great.
Terry L - 02/12/2018

2013 Ford Focus

I installed the kit in an afternoon with out complication. I am mechanical but I'm not a mechanic. To make sure things went smooth, I watched the video and took my time. It's been a year and my lights work as they should. I saved a lot of money and the time it took was worth it, to me.

2012 Ford Focus

After a few months one of the lights died. Measured voltage with a meter and found to be all over the place. Now a bit over a year later the entire module is dead. Avoid this product!

2013 Ford Focus

This product works well and installs very easily. The only difficulty in installing this kit is running the 12V power wire to the battery. I wish the interior design of the car would have been more forgiving, but it wasn't too bad.

2012 Ford Focus

Installed perfectly last summer. No longer working. Disappointed! Traler lights fine on other vehicles.


This light kit is exactly as advertised.
I followed the video instructions that were sent with my order confirmation. Everything worked just as the video instructed.
Just as a footnote, I also ordered and installed a trailer hitch from etrailer and it also installed just as the video instructed.
Great products, super fast shipping and superior customer service!

2012 Ford Focus

I am not a mechanic, but the video makes this installation very easy. This saved me so much time. I couldn't be happier with All of my purchases and installs have gone BETTER than expected. I highly recommend buying this. Traler lights are working great.

2013 Ford Focus

I'm an electrician and I found the quality to be premium. Only one issue I accidentally ordered 2 of them and I was extremely busy at the time and I never opened the second one. Would you guys like to buy it back at a lesser price? I have no need for it and I did keep it inside a house.

Thanks for the follow up. I have provided a link to our returns policy for your reference.
-- Etrailer Expert Rachael H - 08/01/2017

by: 06/20/2021

Watched the video and went together just like it showed and trailer lights worked


Good product, ran the battery power suppy wiring through the (inside) of the car though, so the wiring isn't exposed to the harsh Minnesota and Wisconsin winters. Wiring install diagram (included with wiring) is a bit vague, and install video makes it look somewhat easier than it really is.


Product worked great. Still working without issue after a year. Install took some work and figuring out all the crevices to fit cords through, but the install instructions and videos were very helpful.

2013 Ford Focus

Haven't gotten the chance to use it yet, but In terms of installation, the videos on this website walk you through every step of the way. Good quality harness.

2013 Ford Focus

Bought this and was very easy to install...
me no more than 40 minutes.
Instructions were easy to follow, and had video to help identify locations more readily.
Still works, no issues.
Installed on 2013 Ford Focus SE hatchback.

2012 Ford Focus

wire harness went on as instructions detailed , everything works perfectly , would recommend and will shop with E-Trailers again.

Show More Reviews

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

  • Would Performing a Battery Test Fry a Trailer Wiring Harness on a 2012 Ford Focus
    If the yellow fuse holder wire from wiring harness # 118549 was pulled out at the battery then it would not have done anything to the converter box. What might have happened is some part of the system when attached to the battery touched something else and melted or burned something but that is speculation. The trailer lights get the power from that connection to the battery so if it is not connected or the fuse is blown then it will not work. If it is all connected and the lights are...
    view full answer...
  • Recommendations for Running 12V Power Wire on 2012 Ford Focus Trailer Wiring Harness 118549
    In order to protect your vehicle wiring, it is really best to run the 12V power wire up to the positive battery terminal in the engine compartment of your 2012 Ford Focus. This ensures that you have a direct connection to a 12V source, and that there nothing else pulling power off the same wire. When you tap in at the rear of the vehicle, you run the risk that other functions or accessories have been connected to the same 12V line, which could cause an overload or back feed of power...
    view full answer...
  • Removing the Tail Lights on a 2012 Ford Focus Hatch Back for Trailer Wiring Installation
    You will need to remove some trim panels in the rear cargo area of your 2012 Ford Focus in order to gain access to the tail light wiring. If you look at the instructions I have linked for the Curt wiring harness, # C56140, there are some helpful pictures. The tail lights may need to be persuaded slightly because the seals around them can stick. If there are additional fasteners holding on the lights, they may be revealed when you remove the trim panels in the cargo area.
    view full answer...
  • Trailer Wiring Harness for a 2014 Ford Focus ST Hatchback
    Yes, trailer wiring harness # 118549 will fit your 2014 Ford Focus ST hatchback. I have included a link to the installation instructions and a link to a video showing a typical installation for you.
    view full answer...
  • Trailer Wiring Harness Recommendation for a 2014 Ford Focus ST Hatchback
    For your 2014 Ford Focus ST hatchback the trailer wiring kit part # 118549 has been confirmed as a fit and would work well. I attached an install video for you to check out as well.
    view full answer...
  • Trailer Wiring Recommendation for a 2013 Ford Focus Hatchback
    Yes, we do carry trailer wiring for your 2013 Ford Focus Hatchback. You will want the Tow Ready wiring harness part # 118549. I attached an install video for you to check out as well.
    view full answer...
  • Trailer Wiring Harness for a 2017 Ford Focus Hatchback
    The trailer wiring harness shown for the 2017 Ford Focus hatchback is # 118674. However I did find in one manufacturer fit guide that # 118549 will fit despite being listed up to 2014 models only in many other fit guides. Based on several fit guides and other information it would seem that # 118674 is correct. It is a 6-pin set up though the connectors are more like rounded squares.
    view full answer...
  • Trailer Wiring Harness Recommendation for a 2015 Ford Focus Hatchback
    For the hatchback models of the 2015 Ford Focus the correct trailer wiring harness would be the Tekonsha harness part # 118674 which has been listed as a fit.
    view full answer...
  • Installing LED Tailgate Light Bar on 2014 Ford F250 Using # 118158 Vehicle to Vehicle Converter
    What you are wanting to use is separate signals from the brake lamp and the turn signals. Using the 118459 would actually get you the opposite of what you're looking for. Use the # 118158 converter, and wire the inputs into the wiring feeding your trailer connector. The converter will separate out the brake signal for you. The orange wire from your light bar would connect to the red output wire from the converter. The green and yellow wires from the light bar would connect to the green...
    view full answer...
  • Correct T-One Wiring Kit for 2013 Ford Focus Sedan and Hatchback Models
    If your 2013 Ford Focus is a Sedan you need the T-One # 118548 but if your Focus is a Hatchback you need the T-One # 118549 instead. Both options tee in behind the tail lights of the vehicle and pull power directly from the battery via the included lead but the difference is the connectors that tee in. The Sedan and Hatchback models use different connectors for the tail lights for the OEM wiring so it is important to make sure you get the correct kit.
    view full answer...
  • Trailer Wiring Harness Options for a 2012 Ford Focus Hatchback
    There are 2 possible wiring harness options for the 2012 Ford Focus Hatchback. You could use Curt wiring harness, # C56140, that you have referenced. The other option is Tow Ready wiring harness # 118549. I have included links to the instructions for both harnesses. Both harnesses install the same way and require a direct connection to the battery to power the trailer lights. This protects the vehicle electronics. The more popular harness is the Tow ready, # 118549, harness.
    view full answer...
  • Coiled Tow Bar Wiring Extension to Go from a 7-Way to a 4-Way Flat
    Yes, the tow bar wiring harness # HM56008 will work as a combined system, with the brake lights and turn signals on the same circuits. You could use ta 7-Way to 4-Way adapter either directly in the 7-Way on the RV or at the end of a coiled extension. But I was able to find a nice long coiled cable to go from a 7-Way to a 4-Way, # 787196.
    view full answer...
  • Trailer Hitch & 4-Pole Wiring Harness Fits for 2014 Ford Focus Hatchback
    The 1-1/4-inch Class I hitches made for your 2014 Ford Focus Hatchback are all shown on the linked page. Some of these fit both the hatchback and the sedan versions while Curt # C11431 only fits the hatchback. We do not have CAD drawings but since these are custom-fit hitches made specifically for your car you can be confident of their fitting properly. All hitches use the same mounting points on the car's frame. Of all the options I suggest Draw-Tite # 24872 both for its lower price and...
    view full answer...
  • Towing Capacity of Trailer Hitches that Fit 2009 Toyota Corolla
    In general we have lower weight capacities for vehicles here in the US when compared to other countries. Most agree it's because we are a bit more lawsuit happy than other countries. That said for your 2009 Toyota Corolla the highest capacity hitch we have has a 2,000 lb total trailer weight capacity and a 200 lb tongue weight capacity like the Draw Tite part # 24913. For trailer wiring then you'd want the part # 118549 which is an easy install and very reliable and then for a ball mount...
    view full answer...
  • Plug and Play Tow Bar Wiring Harness for a 2012 Ford Focus SE Hatchback
    Trailer wiring harness # 118549 gets the signals it needs through the tail light wiring on your 2012 Ford Focus hatchback. The power for the trailer lights comes from the connection to the vehicle battery. This wiring harness is if the Focus is towing a trailer and will not work in reverse (towing the Focus behind a motor home). For a similar harness that is set up to work as tow bar wiring and that plugs inline with the tail light wiring use # HM56008. The harness gets its power from...
    view full answer...
  • Trailer Hitch Recommendation for 2012 Ford Focus for Towing Trailer
    I wish we had a carrier solution that I could recommend, but all of the hitches for your 2012 Ford Focus like the Draw Tite # 24872 do not have the capacity for a scooter carrier like you'd need. Only possible solution would be a trailer for the scooter with the hitch. For trailer wiring you'd want the part # 118549 for if you have a hatchback or part # 118548 for if you have a sedan. For a ball mount you'd then want the part # 3593 and hitch ball # 19256.
    view full answer...
  • Using Ford LED Hitch Cover on a 2014 Ford Focus when Flat Towing and When Driving
    Since you are towing the Focus behind the RV, you would not use wiring harness # 118549 for that purpose. This harness would be used for the Focus to tow a trailer and not to tow the Focus with the motor home. I do understand what you are trying to accomplish though and why you selected that harness; the Ford LED hitch cover # CR-017F has to plug into something! But if you want to use the cover all of the time and not just when flat towing the Focus you will need to have the wiring harness...
    view full answer...
  • Towing a Motorcycle Trailer with Separate Brake Lights and Turn Signals with a 2013 Ford Focus
    The issue is that motorcycles and the trailers made for them usually have separate turn signal and brake light circuits. But on trailers towed by passenger vehicles, the turn signal and brake lights are combined. Basically, you will have to make an adapter. You will need 3 important parts. First you will need a vehicle to vehicle converter # 118158. Next, a trailer side 4-Way, # 18004. And finally a vehicle side 5-Way, # 20016. It will be assembled like in the picture I have provided...
    view full answer...
    Image 1 for
  • Trailer Hitch and Towing Components Needed for 2014 Ford Focus
    The towing capacities of a vehicle are typically very conservatively figured so as long as you are staying under the capacity of your 2014 Ford Focus you'd be totally fine. For your 2014 Ford Focus the Draw Tite hitch part # 24872 would be the hitch to go with. This fits sedans and hatchback models too. For trailer wiring you'd then want the part # 118549 for if you have a hatchback or part # 118548 for if you have a sedan. Tekonsha wiring kits are the most reliable so they are what we...
    view full answer...
  • Installing a Trailer Wiring Harness on a 2012 Ford Focus
    It depends on what wiring harness you are using on your 2012 Ford Focus. If you are using a hardwire harness where you have to find and splice in the wires from the harness to the tail light wiring on the vehicle, you will need to use a circuit tester to find the correct wires on the vehicle. If you do not have a circuit tester you can use # PTW2993. Have someone sit in the vehicle and go through the lighting functions; turn signals, running lights, and brake lights, while you test the...
    view full answer...
  • Hitch and Motorcycle Carrying Options for 2012 Ford Focus Hatchback
    The hitches that are available for your 2012 Focus Hatchback are all Class I hitches, that have a 200 lb tongue weight capacity. This would mean that 200 lbs is the maximum amount of weight that would be suspended from the hitch, which would include the weight of the carrier. I'm sorry to say that you wouldn't be able to carry your bike on a hitch mounted carrier. This being said, you could still install a hitch like the Draw-Tite Hitch # 24872 and carry your bike on a small utility trailer....
    view full answer...
  • Hitch Recommendation for a 2013 Focus ST Towing a Motorcycle Trailer
    The Curt Hitch part # C11431 can tow a trailer that weighs up to 2,000 lbs total and exerts a downward force on the hitch of up to 200 lbs. That's what tongue weight is, the vertical force the weight of the trailer puts on the hitch. If the trailer you plan to tow is under those capacities when completely loaded this hitch would work well for you. You also will want to check the owners manual of your 2013 Ford Focus ST to determine how much capacity your vehicle is rated to tow and be...
    view full answer...
  • Hitch, Ball Mount, Trailer Ball, and Trailer Wiring Harness for 2014 Ford Focus Hatchback
    The hitch needed will depend on if your Focus is an ST model. If it is, you'd need the Curt Class I hitch, part # C11431. If it's NOT an ST model, you can use the Curt Class I # C11158, as long as your vehicle isn't an electric model. The recommended ball mount for either of them is part # C45521. Part # 19256 is the recommended 1-7/8 inch trailer ball and part # 118549 is the trailer wiring harness. You also need part # F-4 for the pin and clip.
    view full answer...
  • Installation Photo of EcoHitch Hidden Hitch on 2012 Ford Focus Electric
    I have attached a photo of the EcoHitch Hidden 2 Inch Trailer Hitch Receiver installed on a 2012 Ford Focus Electric. The hitch is designed to fit 2012 through 2014 Ford Focus Electric vehicles. If you're in the market for a bike rack, the Swagman XTC-2 2-Bike Platform Rack # S64670 would pair up nicely with the EcoHitch receiver. If instead, you plan on towing a small trailer, you may consider the following parts to complete your towing package: # 118549 - 4-Pole Flat Trailer Connector...
    view full answer...
    Image 1 for

< Previous

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 Mike L
Expert Research:
Mike L
Employee Sarah L
Expert Research:
Sarah L
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Zack K
Video Edited:
Zack K
Employee Andrew L
Video Edited:
Andrew L
Employee Dustin K
Video Edited:
Dustin K
Employee Andrew K
Video by:
Andrew K
Employee Nicholas E
Test Fit:
Nicholas E
Employee Shane T
Test Fit:
Shane T
Employee David F
Test Fit:
David F
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Updated by:
Alexander C
Employee Isabelle B
Updated by:
Isabelle B
Employee Cole B
Installed by:
Cole B

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.

Product Experts Available Now!
Call 1-833-496-1390