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T-One Vehicle Wiring Harness with 4-Pole Connector

T-One Vehicle Wiring Harness with 4-Pole Connector

Item # 118779
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Custom Fit Vehicle Wiring

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118779 - 4 Flat Tekonsha Trailer Hitch Wiring
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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. 1-833-496-1390 to order Tekonsha custom fit vehicle wiring part number 118779 or order online at Free expert support on all Tekonsha products. Guaranteed Lowest Price and Fastest Shipping for T-One Vehicle Wiring Harness with 4-Pole Connector. Custom Fit Vehicle Wiring reviews from real customers.
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Tekonsha Custom Fit Vehicle Wiring - 118779

  • 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 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: 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.

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 beneath and to the center of the vehicle. A mounting bracket (sold separately) is recommended to keep the connection secure.

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.

118779 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details 118779 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Connector - 118779

Average Customer Rating:  4.8 out of 5 stars   (87 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 Jeep Cherokee

Another great Tekonsha product. Install was super easy and exactly as destribed in the instructions. The only area for improvement that I noticed during installation is that it would be nice if the wiring from the rear light connections to the Tekonsha control box could be slightly longer both on the driver side but especially from the control box to the passenger side light connections. This would allow for a few more mounting options for the control box but even without that, everything fit and functioned as expected.

2020 Jeep Cherokee

I had this wiring harness and the Curt Trailer Hitch Receiver (Item C1335) installed at the same time on my 2020 Jeep Cherokee. I had a local independent garage do the installation since I do not have a lift. I questioned them as to how easy it was to install this item and they said it went very well, The worst part was routing the hot wire up to the battery. The mechanic was very meticulous about routing the wire so it was hidden and well protected. Overall they thought this kit was very high quality. Also, the videos are a great help to see just how it's supposed to be done! Nice job on your part!!

Absolutely no issues what so ever. Highly recommended.
Jon S - 11/15/2021


This package worked absolutely perfectly with my 2021 Cherokee Trailhawk. My only suggestion is that this setup substantially cuts down on your departure angle. Serious off-roaders beware. Not an issue for the majority of my applications. This is my second purchase from etrailer. Both times it was a painless process. Quality products, a very knowledgeable staff, and quality service and follow up. I couldn't be more satisfied with my experience.


This is the second harness that I have purchased. Easy to install and works as described. I would purchase again and would not hesitate to recommend to friends and family, and maybe even an enemy ;-)

All said, great product!


You can't get much better than this. Everything exactly as I needed, great instructions, good prices, quick delivery. I don't bother messing with anyone else. I've done a lot of utility with this little Jeep Cherokee pulling a trailer, and it has not let me down. Very pleased. Thanks, etrailer!


Excellent products and easy to install !!!!


This the cleanest way to splice into existing wiring to setup tow car lightening. We have towed our car over 10,000 miles without a problem with the lights.

2019 Jeep Cherokee

Installation was easy did it by myself wiring went well too. 2019 Jeep Cherokee


Very easy and quick to install. I removed the lower bumper shroud and nothing more. Fits perfectly around the muffler and required no cutting of anything.

2019 Alfa Romeo Stelvio

Bottom line..
eTrailer is tops in my
book with anything trailers and hitches. Carol was able to work out the best solutions for me, and I can't remember who I followed up with regarding my wanting the trailer Tekonsha harness for my Jeep, but they were super too!

See my picture in Carol's email (attached)!

No doubt the talking (phone), and helpful videos for exactly my brand of Jeep were instrumental in making the installation easier and faster.. with a lot less banged knuckles ;-)!

You Guys and Gals Rock!
[Thumbs up]


Working with etrailer was a breeze, and getting the best/exact hardware and advice for my trailer needs, wiring requirements and solutions was 100% on point. It was a great help to have the exact videos and background information about installation, best methods and things to look out for.. during my hitch setup! They are heads and shoulders above all others in support, products, and service! A+

2019 Jeep Cherokee

I use this for my kayak trailer, it was easy to install and a great value. I also bought my trailer hitch which i installed on my 2019 Jeep Cherokee.. another great value and easy to install. I had one question with installation of the hitch and etrailer answered the phone within 3 rings and helped me out.

2019 Jeep Cherokee

Everything went well till I ran the wires to the passenger side the red wire was not as long as the green. Did not have enough to get the wires up to plug them into the light that is the only complaint other than that they work fine

Not so well
George E - 06/11/2020

Can you tell me

-- Etrailer Expert Heather A - 6/11/2020


Everything was set up so simply just very easy to run and hook everything up my 10-year-old son could’ve done it

2020 Jeep Cherokee

Correct parts, plenty of zip ties. Easy to install. No issues.


Worked out fine, DIY install. Zip ties were not long enough to tie wires to hitch behind facia like the video. NO big deal had longer zip ties on hand.


Install was very simple and supplied with all components needed


As always E Trailer has exceptional service and fast Delivery.

I bought the plug and play wiring kit for two Jeep Cherokees and a Chrysler 300. All of them were truly plug and play and I haven’t had a problem with either one.
Robert S - 05/19/2020

Jeep Cherokee

This kit was Awesome! Fit the GFs Jeep perfect. easy to do while installing the hitch! Just unscrew a few screws and pop out the tail lights, plug in and put the tail lights back in. For the Jeep Cherokee, I unbolted the driver side skid plate and zip tied the power wire to a break line and put the skid plate back. crimped the power wire and fuse wires and tied it to a power post under the hood! Easy Peasy!


Ordered the hitch and wiring kit for the trailer lights on the website, had it within a week and the install of the hitch and wiring was fairly quick and simple. All the hardware was included and everything has held up great. Overall a very solid product!


One year review. Pretty easy install. Connectors are perfect and made that part easy. Running the power wire up to the battery is the hardest part. Still working just fine.
Good buy and I would highly recommend both this and etrailer too.


A very easy install, especially if you have a hydraulic lift. Without a lift, you'll crawl around on the ground and reach for a few Advil tablets the next day! I hid and protected the + wire by unbolting the escutcheon that covers the underside of the car. If you haven't already undercoated your vehicle, I recommend having it done it AFTER you install the wiring. A freshly undercoated car is a mess to install anything on especially if it involves contact with the underside of the vehicle. For a fish, I used a simple strand of nylon cord with a small nut on the's a straight run to the underside of the car and gravity makes for a good companion. I removed the 4 bolts that attach the plastic bumper to the underside of the body when it came time to hide the wires connecting the left side to the right side (makes for an easy and attractive installation).

2021 Jeep Cherokee

product was great..the box did not arrive in very good shape .had a big hole in the side but all the parts were there so all was good.


This a high quality part and is easy to install if you follow the video.


Hitch fit good, my neighbor helped me install it.used several times and very satisfied with it.

Show More Reviews

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

  • Aftermarket Trailer Wiring Harness for a 2019 Jeep Cherokee
    For your 2019 Jeep Cherokee, the T-One Vehicle Wiring Harness part # 118779 is a confirmed fit and will work for you. This is a brand new wiring harness that was developed specifically for the 2019 model year and that is all it will fit. This is not an OEM harness like something you would find in a dealer catalog as it is an aftermarket part that is supplied and test fit by third party manufacturers such as Tekonsha. In regards to the activation of the tow package wiring, that will only...
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  • Will Installing an After Market Wiring Harness Void Any Parts of My Warranty on a 2019 Jeep Cherokee
    If you splice into factory wiring that can be an issue with warranty, but if you use an aftermarket harness like the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Connector # 118779 on your 2019 Jeep Cherokee you will be fine. The harnesses like this that don't alter the factory equipment in any way cannot void your warranty. You will be protected by the Magnuson–Moss Warranty Act. This act states, in part, that unless the installation and the part caused a problem then the warranty...
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  • Troubleshooting T-One Trailer Wiring Harness Where Vehicle Tail Light Comes On and Then Goes Out
    I was able to check your previous invoice and found the T-One Vehicle Wiring Harness with 4-Pole Connector # 118779 for your Jeep Cherokee. It sounds like it is drawing power from your right side wiring harness when it should be pulling power directly from the battery. I recommend checking the power wire, the integrated fuse, and the ground wire connection.
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  • Troubleshooting Trailer Wiring Harness Installation on 2020 Jeep Cherokee
    We can absolutely help you troubleshoot this. When installing a wiring harness like the Tekonsha # 118779 on your 2020 Jeep Cherokee, this most commonly occurs when one of three things happens; either the plug is not seating correctly with the harness, there is a blown or missing fuse, or the ground wire is not sufficiently connected. In this case, checking the ground connection is always the easiest and first thing to look at; check to make sure it is firmly connected to a paint and debris...
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  • Trailer Wiring Recommendation for 2019 Jeep Cherokee Latitude
    For your 2019 Jeep Cherokee Latitude the best trailer wiring option is the Tekonsha part # 118779 as it installs the easiest and has the most reliable converter box as well. I attached an install video for more info on this as well.
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  • Will Tekonsha 118779 Turn Off ParkSense Feature of 2019 Jeep Cherokee When Backing a Trailer
    The Tekonsha # 118779 will NOT turn off the ParkSense feature of your 2019 Cherokee, but luckily enough, the folks at Jeep had the good sense to make a provision that allows you to turn off that feature temporarily. You can turn on and turn off ParkSense with the ParkSense switch located below the Uconnect display. When the switch is pushed to disable the system, the display will show 'ParkSense Off'. When the shifter is moved into reverse while the system is disabled, the display will...
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  • Troubleshooting Right Side Trailer Light Staying On After Working Correctly A Few Times
    Based on the issue you are describing it sounds like the white ground wire on the Tekonsha # 118779 is not making a good connection to your 2020 Jeep Cherokee. I recommend picking a new spot on your Jeep to secure the white wire to, making sure that it is bare, corrosion free metal. If that does not fix the issue the I recommend double checking that all of the connectors are still secured, and have not come loose after driving around a while. I included a video of the # 118779 being...
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  • Recommended Custom Fit 4-Way Connector Harness For 2022 Jeep Cherokee
    There sure is! For your 2022 Jeep Cherokee I recommend the Tekonsha T-One Vehicle Wiring Harness # 118779 which is specifically designed for your vehicle so it will plug in to your factory connectors and will require no splicing. You will need to run a wire from the black wire on the harness to the positive terminal of your vehicle battery with the included in-line fuse to protect your factory tail light circuits from being overloaded or damaged by back feed. I included a video of the...
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  • Trailer Hitch Recommendation for a 2019 Jeep Cherokee
    Yes, the Draw-Tite trailer hitch, part # 75998, does fit your 2019 Jeep Cherokee. The installation is basically the same as the 2018 model so I've linked the video you mentioned. The wiring harness that fits is part # 118779. I've also linked a couple of articels you might find helpful. As well as some links to our selections of other parts you might need to tow with your Jeep.
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  • Hidden Trailer Hitch and Wiring for 2021 Jeep Cherokee
    For your 2021 Jeep Cherokee we have the mostly hidden Draw Tite part # 75998 as a fit that would work great. It has only the hitch opening that hangs below the rear bumper so it's mostly out of sight. I attached an install video for this for you to check out as well. If you needed trailer wiring as well the Tekonsha kit part # 118779 is a great option that installs easily and is very reliable.
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  • What 4-Pole Wiring Harness will Fit My 2021 Jeep Cherokee?
    For a great 4-pole wiring harness that will get the job done on your 2021 Jeep Cherokee, I recommend the T-One Vehicle Wiring Harness with 4-Pole Connector # 118779. This harness will give you brake light, running light, and turn signal functionality. If you need a ball mount and ball like what is included in the etrailer Ball Mount Kit for 2" Hitches - 2-3/4" Rise or 4" Drop # 989892. If you need an additional rise or drop for the mount, I linked a product page of all of our available...
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  • Hitch and Trailer Wiring Harness Recommendation for 2020 Jeep Cherokee Latitude
    For your 2020 Cherokee Latitude, I'd recommend going with the Curt # C13395 Class III receiver hitch you'd looked at. The hitch is designed so that the crossbar will be concealed behind the rear bumper, with only the receiver tube and safety chain loops being visible. For a trailer wiring harness, I'd recommend the Tekonsha # 118779 T-One harness. The harness will plug inline using the connectors that attach the taillight assemblies to the vehicle's taillight wiring harnesses. If you...
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  • Recommended Trailer Hitch and Wiring for 2020 Jeep Cherokee Latitude Plus
    Starting with the trailer hitch for your 2020 Jeep Cherokee Latitude Plus, I highly recommend the Curt Class III # C13395 because of its hidden-crosstube design and superior black powder coat finish that lasts longer than those from other manufactures. This Class III hitch also offers the highest tongue weight capacity available for your Jeep and is assembled right here in the USA. The hidden nature of this hitch allows only the 2" receiver to be visible on the Jeep, maintaining a clean,...
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    Image 1 for Image 2 for
  • Custom 4-Pole Wiring Harness for 2020 Jeep Cherokee
    The Curt 4-pole wiring harness # C56406 and the similar Tekonsha # 118779 will work great on a 2020 Jeep Cherokee without the factory tow package being present. I recommend the Tekonsha kit because in our experience their wiring products are the most reliable. Both of these custom-fit kits plug in to the wiring at the tail lights and they will give you a 4-way flat trailer connector. These harnesses feature a powered tail light converter that will protect the vehicle's internal wiring from...
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  • Recommended Trailer Hitch for 2019 Jeep Cherokee
    For your 2019 Jeep Cherokee I recommend the Curt Class III Receiver Hitch # C13395 for a couple of reasons. I really like the hidden design on this particular hitch that allows for only receiver portion to be visible from the rear of the vehicle. This makes for a more sleek, OEM appearance with the hitch installed. I have also attached an image that shows this. In addition to its hidden design this Class III hitch is also made right here in the USA. I have attached the complete installation...
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    Image 1 for
  • Will Installation of a Trailer Hitch and Wiring Void Warranty on a 2019 Jeep Cherokee Latitude
    Installing a trailer hitch like the recommended Curt # C13395 and wiring like the T-One # 118779 that you referenced will not void the warranty on your 2019 Jeep Cherokee Latitude unless the problem was the direct result of the installation. This is covered under the Federal Magnuson-Moss Warranty Act.
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  • 7-Way/4-Way Kit for 2019 Jeep Cherokee Trailhawk Similar to Factory Wiring Setup
    I looked up the factory hitch and wiring kit for your 2019 Jeep Cherokee and the style of connector is the # HM11141144 which you could install on your vehicle but you'd want to use the 4-way kit part # 118779 as an easy way to get the trailer taillight functions first. This is custom fit for your vehicle and you could cut off the 4-way so that you could wire the harness to the 7-way and you'd be set.
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  • Trailer Hitch Receiver Compatible with 2019 Jeep Cherokee Latitude
    For your 2019 Jeep Cherokee Latitude I recommend the Curt Trailer Hitch Receiver - Custom Fit - Class III - 2" # C13395 which is a confirmed fit for the Latitude model. If you will be towing with this hitch receiver then the T-One Vehicle Wiring Harness with 4-Pole Connector # 118779 is my recommendation as it connects to the factory wiring harness behind the driver and passenger side tail lights.
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  • Can Both Trailer Wiring and Flat-Tow Wiring Harnesses Be Installed On a 2019 Jeep Cherokee
    I have a great option that will allow you to illuminate the taillights on the towed vehicle while in tow as well as the lights on a trailer while being towed with said towed vehicle. For the first part, I recommend the Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit part # RM-15267 and then for the second part I recommend the T-One Vehicle Wiring Harness with 4-Pole Connector part # 118779. The two won't interfere with one another.
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  • Will Curt Trailer Hitch C13395 Fit 2019 Jeep Cherokee Latitude
    I checked with Curt, and can confirm that the Curt Trailer Hitch Receiver # C13395 is a fit for your 2019 Jeep Cherokee Latitude; it will fit even though your backend looks somewhat different. The chassis is the same so it will bolt on the same way. You can still use the video (which I linked for you below) as an install guide for your Jeep Latitude of the Curt Trailer Hitch Receiver # C13395. If you were planning on using your Jeep for towing, and needed a trailer wiring harness as...
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  • What Trailer Hitch do You Recommend for Towing a Light Camper on My 2021 Jeep Cherokee?
    Starting with the trailer hitch for your 2021 Jeep Cherokee, I highly recommend the Curt Class III # C13395 because of its hidden-crosstube design and superior black powder coat finish that lasts longer than those from other manufactures. This Class III hitch also offers the highest tongue weight capacity available for your Jeep and is assembled right here in the USA. The hidden nature of this hitch allows only the 2" receiver to be visible on the Jeep, maintaining a clean, OEM appearance...
    view full answer...
    Image 1 for Image 2 for
  • Trailer Hitch Recommendation for 2020 Jeep Cherokee Latitude
    For a trailer hitch that fits your 2020 Jeep Cherokee Latitude I would recommend the Curt hitch part # C13395 as it is mostly hidden, installs easily and has great towing capacities. If you need trailer wiring the Tekonsha kit part # 118779 would be a great option that is easy to install and has most reliable converter box.
    view full answer...
    Image 1 for
  • Recommended Trailer Hitch For A 2019 Jeep Cherokee Trailhawk
    When installing a trailer hitch on your 2019 Jeep Cherokee Trailhawk The Curt Trailer Hitch Receiver - Custom Fit - Class III - 2 inch # C13395 will work. The hitch has a bolt-on installation, and has a gloss black powder coat finish over the protective base coat that offers superior rust resistance. The hitch is made in the USA. I also recommend The T-One Vehicle Wiring Harness with 4-Pole Connector # 118779. It has a simple plug and play installation that plugs in behind the driver...
    view full answer...
  • Trailer Hitch and Wiring for a 2019 Jeep Cherokee Trailhawk
    Yes! Curt trailer hitch # C13171 is indeed listed as a fit for your 2010 Jeep Cherokee Trailhawk. I have linked a video showing an example installation for you. This hitch is a great option for a bike rack. The 2 inch receiver will afford you many options if you do not already have a bike rack. If you need a bike rack recommendation just let me know how many bikes you will need to carry. If you do plan on towing in the future I recommend etrailer ball mount kit # 989900. It comes with...
    view full answer...

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Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Jameson C
Expert Research:
Jameson C
Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Joshua S
Video by:
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Video by:
Michael B
Employee Jacob T
Video Edited:
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Employee Dustin K
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Updated by:
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