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

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

Item # TK99FR
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Custom Fit Vehicle 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. 1-636-306-4830 to order Tekonsha custom fit vehicle wiring part number TK99FR 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.
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  • Reviews (138)
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Tekonsha Custom Fit Vehicle Wiring - TK99FR

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


Features:

  • 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 the trim panel near the driver's side rear seat belt bracket
    • Plug in T-connector
  • 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


Specs:

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


Installation

This custom-fit T-One connector plugs into your vehicle's wiring harness, which is located behind the trim panel near the driver's side rear seat belt bracket. You will have to pull back the side trim panel to access this harness.


Once installation is complete, the 4-way flat connector will be stowed beneath your vehicle, near the trailer hitch. A mounting bracket (sold separately) is recommended to keep the connector 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 your vehicle runs on a multiplex wiring system, the wiring needs to be converted to be 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.



118827 Tekonsha T-1 T-Connector - 4 Wire - Modu-Lite Converter Included

Installation Details TK99FR Installation instructions

This Product Fits The Following Vehicles





Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - TK99FR

Average Customer Rating:  4.9 out of 5 stars   (138 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.

by:

I don’t generally write reviews, good or bad, but I felt Etrailer was deserving of one. I have purchased several hitches for different vehicles over the years and have nothing but good things to say about Etrailer. Their representatives are always knowledgeable, helpful, and a pleasure to do business with. They get your purchases shipped quickly and provide accurate tracking data. For the DIYSers they have terrific installation videos for nearly every make and model. Thanks Etrailer for your service!




by:

I’m grateful for a company like etrailer. Although it took longer than expected to get the part, that was out of your control due to supply chain issues created by the current administration. As far as etrailer, you’re my go to place for anything trailer. Easy to locate the part on your website. I especially like the videos you provide to show how to install on particular models and configurations. Will always go to etrailer for my trailer needs.




by:
2022 Toyota Highlander

Works exactly as stated. This is much better than cutting/splicing into the car's wiring. (like we did back in the day!)




by:

This wiring was the most simple I have ever seen! As a retired automotive technician I have wired many trailers. The connectors fit perfectly and the video instruction was superb. I took my time and maybe spent 1/2 hour to do the install. Tested circuits after installation for function on my 2020 highlander hybrid. Works perfect.




by:
Toyota Highlander

Video instruction made this amazingly simple. Installed on 2021 Toyota Highlander Platinum — plug and play. Bought from etrailer because of the time they spend on customer-facing these products. I’ll support the thorough reviews and detailed instructional videos all day. Keep up the good work!




by:
Toyota Highlander

Easy installation and worked great on my Highlander. The videos were a great help and additional details for the install.




by:

This product fit as advertised and installed exactly as the video showed. My Highlander is a 2021 Hybrid so I was worried there would be something strange or different than other Highlanders but once I found the harness connector under the bumper (exactly where the video said I would) I knew this would work. I HATE pulling plastic panels! I've broken too many clips, but this is a new car and the video showed me just where to go. The connector inside the rear panel was tied up and I elected to leave it that way to prevent rattling. Once I got it mated to the TK99FR cable it was easy to stow. Under the car, the harness connector is stowed with a plastic clip so be careful pulling the cap off (I think it was broken in the video). There was plenty of wire to reach the bracket on the hitch plate. That bracket (item #18144) was too tall to fit upright between my hitch an bumper so I mounted it as best I could so it wouldn't hang too low. I think it's important to put the head of the screw closest to the wires as the nut and threads can chafe. The 4_pole connection is a very tight fit into the bracket and I'm glad for that. I don't think it will be pushed out by mating with a trailer connector. Extremely happy with the results!




by:

Got just what I expected, very easy install just plug it in and done
E trailer makes it very simple with there install videos
Thanks e trailer !!




by:
2022 Toyota Highlander

I thought I could get away with just the trailer connector, but as I didn’t have the towing option on my 2022 Highlander, I needed this full kit. Just follow the simple instructions, and you should be able to connect everything in about 20 minutes. Great product.




by:

The T-Harness works fine - the only issue I encountered involved identifying the correct harness connector located behind the driver side panel near the third seat. There is another harness and connector nearby and identification of the correct one vs. the incorrect one could be improved...once I figured that part out there were no other issues.




by:
2022 Toyota Highlander

Thanks to the excellent eTrailer video had the wiring installed in my new "22 Highlander in a short amount of time. I like doing things myself and saving some money - eTrailer helps me with that!




by:

Installed with ease and worked the first time. There are several [online] videos out there to help with the install. But I recommend viewing the one from etrailer. The hitch works and looks fantastic.




by:
2022 Toyota Highlander

Excellent product at good price. Good instructional video on how to install wiring harness. Fast delivery. Thank you etrailer.




by:

So far so good. Wasn't hard to install by myself even though it weighs 50lbs (set it on milk cartons). Haven't used it yet but will soon. The trailer wiring was easy to install.




by:
2010 Toyota Highlander

Quick delivery and easy install in our 2021 Toyota Highlander. Instructions didn’t point out the two 10 mm bolts you need to remove for the install but it was pretty easy to figure out. One is located above the cup holders underneath the black plug and the other is visible when you remove the cup holder.




by:

Great instructions for the install. Worked great, not issues no complaints!




by:
2020 Toyota Highlander

Installation was just as described in your video and everything works well. Thanks.




by:
2020 Toyota Highlander

Installation was simple using e-trailers video.




by:

I tried another brand of wiring harness for my Toyota Highlander 2021 but it didn't fit properly. etrailer sent me Item #TK99FR and I returned the other harness for credit. The T-One was simpler to install, basically "plug and play" with no splicing required. There is also a comprehensive video on the etrailer site that shows you how to install it. The installation was a slam dunk, taking about 30 minutes including watching the video. It worked perfectly once installed. Michelle was a big help in making sure I received the right wiring harness for my new Highlander.




by:
2021 Toyota Highlander

Easy installation and worked good




by:

Fairly easy to install, video was a great help. The big issue was the item delivered with a different product number then the item actually ordered. The picture on the box was different than the wire harness ordered which caused some confusion. I opened box and it was the harness ordered but with a different picture and item number?


Comments
I understand your worry. TK99FR and 118827 are the same part. One is our web sku number and one is the manufacturers number.
-- Etrailer Expert Sierra K - 08/24/2021


by:

I bought the wrong part initially and had to pay for shipping it back but once I got straightened out by the e trailer sales staff on what I needed to buy (e trailer knew more than my local dealership), everything worked out great.




by:

I installed this on my 2022 Toyota Highlander. It was a lot easier to install then I thought. The module inside the back driver side panel was challenging but simple.




by:
2020 Toyota Highlander

Must watch the installation video first, and then actual installation process is very straightforward. I didn't have to use the trim remover for the 3rd trim. Outside 4pin connector is just a snap. Highly recommended! (2020 Toyota Highlander)




by:

Instructional videos are excellent form selection to installation



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138
Show More Reviews

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



  • No Lights After Installing Trailer Plug On 2021 Toyota Highlander With Tow Package
    The 2021 Toyota Highlanders don't all come with the factory tow package. I have installed many trailer wiring harnesses on this vehicle and I always end up having to switch to the full version for models without the tow package, the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector part # TK99FR. I usually just recommend this option no matter what as you will be covered either way.
    view full answer...
  • Where Does Tekonsha Trailer Wiring Install on 2020 Toyota Highlander
    We don't have any install videos for the trailer wiring that fits your 2020 Toyota Highlander like the T-One part # TK99FR but I did attach an install instructions link for you to check out. It does install in the rear area that you mentioned which you can see in the instructions.
    view full answer...
  • Does The Tekonsha TK99FR Include The Same Parts As The Toyota OEM Parts for 2020 Highlander Platinum
    The Tekonsha T-One Vehicle Wiring Harness # TK99FR does include both the converter and the 4 Flat plug and will be very similar to the OEM Toyota parts you found, just put together in one kit. I included an image that should clear everything up for you as well.
    view full answer...
    Image 1 for
  • What Trailer Wiring Will Work For My 2020 Toyota Highlander
    Though we do have the Tekonsha # TK99FR that will fit your 2020 Toyota Highlander, it is only offered as a complete harness It's a quick and easily install that plugs directly into existing wire. The connection points are behind the trim panel near the driver's side rear seat belt bracket. The harness is constructed of 16-gauge bonded wire. I have attached an installation video link below.
    view full answer...
  • Solution for Needing Tekonsha Trailer Taillight Harness for 2021Toyota Highlander w Converter Box
    I wish that was available by itself but the only way to get the harness of the # TK99FR that has the taillight converter is to order the entire kit.
    view full answer...
  • Recommended 4-Way Wiring Harness for 2022 Toyota Highlander Hybrid Platinum Without Tow Package
    For a 4-way wiring harness for your 2022 Toyota Highlander Platinum Hybrid without the tow package you need the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # TK99FR. When it comes to wiring, we have found Tekonsha to be the most reliable. This wiring harness plugs in to the connection point in the rear of your vehicle and will provide you with a 4-way connection to power your trailer's signal lights. I have attached an installation video for your reference.
    view full answer...
  • Trailer Wiring Harness Recommendation for 2021 Toyota Highlander XSE without Tow Package
    For your 2021 Toyota Highlander XSE without the tow package the trailer wiring kit you will want is the Tekonsha part # TK99FR which installs very easily and has the most reliable converter box. I attached an install video for this kit on a similar 21' Highlander for you to check out as well.
    view full answer...
  • Will # TK99FR Work if There is a Tow Package in Place on 2021 Toyota Highlander
    The T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # TK99FR will work with both models. If you have the factory tow package, you just use the harness that has the 4 pole connected to it. If you do not have a factory tow package, you will need to use both of the wiring harnesses as your vehicle is not set up with a converter box to power the trailer lights. We have hitches available for the 2021 Toyota Highlander also. I recommend the Curt Trailer Hitch Receiver # C99FR.
    view full answer...
  • Recommended Vehicle Wiring Harness For A 2020 Toyota Highlander XLE
    For your 2020 Toyota Highlander XLE you will need the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # TK99FR since your Highlander does not have a towing package. This is actually the same 4-way connector harness as the one for vehicles with the towing package but includes a module to plug into your factory wiring to activate the harness. I included a video of the # TK99FR for you to take a look at.
    view full answer...
  • Will the Curt C99FR Fit a 2021 Toyota Highlander XSE
    We actually have a customer of ours that did successfully install the Curt # C99FR on their 2021 Toyota Highlander with the XSE package, so we do have it listed as fitting. With that being said, they did mention that the exhaust did need to be lowered a bit more than usual, but this does happen sometimes and actually isn't too far out of the ordinary. I included a couple pictures of this hitch installed on their XSE for you to check out as well. If you are going to be towing with your...
    view full answer...
    Image 1 for Image 2 for
  • Trailer Wiring for 2022 Toyota Highlander without Tow Package and Trailer Trailer
    Since your 2022 Toyota Highlander does not have the factory tow package the trailer wiring harness you'd want is the Tekonsha part # TK99FR which is the easiest to install and most reliable. Then for a hitch the Curt # C99FR would be a great option that is mostly hidden and has great towing capacities.
    view full answer...
  • Trailer Hitch and Wiring Recommendation for 2022 Toyota Highlander
    The Curt Class III part # C99FR is a fit for your 2022 Toyota Highlander Hybrid and since it's mostly hidden and has great towing capacities would be a great choice. Then for trailer wiring the Tekonsha part # TK99FR would be a great choice as it is very easy to install and also very reliable.
    view full answer...
  • Will Installing A Hitch On A 2022 Toyota Highlander Make The Hands-Free Liftgate Not Work?
    Though installing the Curt # C99FR hitch on your 2022 Toyota Highlander will limit the area of use for the sensor, I have never seen it completely negate its use. All you need to do is find the sweet spot to the left or right of the receiver opening. It will take a couple times to get used to, but after that it will be second nature and you wont even notice the difference. I included an install video of this on a 2021 Highlander for you to check out as well. As to the wiring, I recommend...
    view full answer...
  • Does Curt Hitch C99FR Fit 2022 Toyota Highlander Hybrid
    The Curt hitch part # C99FR does fit your 2022 Toyota Highlander Hybrid but like all of the hitches that fit your vehicle it will not fit with a spare that is larger 18 inches. Then for trailer wiring you'd want the part # TK99FR which is easiest to install and most reliable.
    view full answer...
  • Trailer Hitch Receiver Fit For 2021 Toyota Highlander XSE
    I can help you out with the correct trailer hitch fit for your 2021 Toyota Highlander XSE; I do understand the confusion as well, because the page states "excluding XSE" and underneath it states "XSE models". What that means is that the hitch fits both the XSE and non-XSE models of 2021 Highlander. So for your 2021 Toyota Highlander XSE, I can confirm for you the correct fit for a trailer hitch is from Curt: - Curt Trailer Hitch Receiver # C99FR I have added a customer review for you...
    view full answer...
    Image 1 for
  • Recommendation Hitch and Wiring Harness for 2022 Toyota Highlander Limited
    I recommend the Class III Curt Trailer Hitch Receiver, # C99FR with a 2" x 2" receiver opening. This fits all trim levels and bolts onto your Toyota Highlander's frame with no welding required. A complete hardware kit and installation instructions are included. For a 2022 Toyota Highlander Limited listed as With Factory Tow Package, I suggest the T-One Vehicle Wiring Harness for Factory Tow Package, # TK74FR. If listed as Without Factory Tow Package, I suggest the T-One Vehicle Wiring...
    view full answer...
  • What Hitch and 4-Way Wiring Harness do You Recommend for My 2022 Toyota Highlander?
    For your 2022 Toyota Highlander, I recommend the Curt Trailer Hitch Receiver - Custom Fit - 2" # C99FR. Not only does the Curt provide you with 500 pounds of gross tongue weight and 5,000 pounds of maximum gross towing weight, it also comes with a superior outer gloss coating over the base coat to give you maximum rust and corrosion resistance. This model is manufactured in the U.S.A. and fits both XSE an non-XSE models. For the 4-way wiring harness, you need the T-One Vehicle Wiring...
    view full answer...
  • Troubleshooting Trailer Wiring Install for 2020 Toyota Highlander that is Not Active
    Sounds like you should have went with the Tekonsha trailer wiring harness part # TK99FR which comes with the harness of the # TK74FR but also comes with the needed converter box harness which you are missing. The converter harness is also not available separately.
    view full answer...
  • 4-Way Trailer Wiring Harness for 2022 Toyota Highlander with and without Tow Package
    For your 2022 Toyota Highlander the correct and best option for a 4-way harness is the part # TK99FR for if you do not have the tow package or the # TK74FR for if you do have the tow package. If you are not sure whether or not you have the factory tow package you'll want to reach out to the dealer but this is almost always listed on the window sticker if equipped. Please note, models without the factory tow package may still have the tow package plug but that does not mean the circuits...
    view full answer...
  • What is the Correct Wiring Harness for 2022 Toyota Highlander with Factory Tow Package.
    The correct wiring harness for your 2022Toyota Highlander with factory tow package is the T-One Vehicle Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector # TK74FR. The # TK74FR is the right wiring harness since you have the factory tow package installed.
    view full answer...
  • Troubleshooting Trailer Wiring Installation for 2022 Toyota Highlander
    If you've securely connected the Tekonsha T-One Wiring # TK74FR to your 2022 Toyota Highlander but you aren't getting any power to the 4-Way then it sounds like your Highlander doesn't have the factory tow package and you needed the T-One Wiring # TK99FR instead which comes with an extra wring piece that activates the tow package wiring on your vehicle. You can double check whether your Highlander has the tow package or not by calling your local Toyota dealer with your VIN. If you don't...
    view full answer...
  • Recommended Made In America Trailer Hitch Receiver For 2020 Toyota Highlander Hybrid Platinum AWD
    Absolutely! For your 2020 Toyota Highlander Hybrid Platinum AWD I recommend the Curt Trailer Hitch Receiver - Custom Fit - Class III - 2" # C99FR which is made in the USA, and will be perfect for carrying a bike rack, a cargo carrier or even towing a trailer due to the 500lb tongue weight rating and 5000lb trailer weight rating. As you mentioned the # C99FR exceeds the capacities of your Highlander so you will need to use the lower rating of the vehicle, but you will have peace of mind...
    view full answer...
  • Recommended Trailer Hitch Receiver For 2021 Toyota Highlander XSE
    There sure is! For your 2021 Toyota Highlander XSE we have the Curt Trailer Hitch Receiver - Custom Fit - Class III - 2" # C99FR which will fit perfectly and has a 500lb tongue weight rating and 5000lb trailer weight rating making it a great option for carrying a bike rack, cargo carrier, or a ball mount to do some towing. If you are planning on towing with your Highlander you will also need a vehicle wiring harness # TK99FR, and a ball mount, hitch ball, and hitch pin and clip which...
    view full answer...
  • Will The Curt C99FR Hitch From A 2020 Toyota Highlander Fit A New 2022 Highlander?
    Moving the Curt # C99FR hitch from a 2020 Toyota Highlander to a new 2022 Highlander will be no problem at all. There have been little to no changes at the back of the Highlander models from 2020 to 2022 so it fits perfectly. However, hitch hardware is really only designed to be torqued down once, so I recommend replacing it with the # RHK replacement hardware kit. This will replace every piece of hardware originally included with the hitch, and actually any hitch brand we carry. Just...
    view full answer...


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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jameson C
Expert Research:
Jameson C
Employee Joshua S
Video by:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Chris R
Video Edited:
Chris R
Employee Wilson B
Updated by:
Wilson B
Employee Noah M
Updated by:
Noah M
Employee Alexander C
Written by:
Alexander C
Employee Shane H
Test Fit:
Shane H
Employee Ryan G
Test Fit:
Ryan G
Employee Michael B
Installed by:
Michael B

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