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  1. Custom Fit Vehicle Wiring
  2. Tekonsha
  3. Custom Fit
  4. Trailer Hitch Wiring
  5. 4 Flat
  6. Converter
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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

Item # 118386
Our Price: $43.17
You Save: 52%
Custom Fit Vehicle Wiring

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Shipping Weight: 0.9 lbs
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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 - no cutting, splicing or tapping required. Circuit-protected converter guards against shorts. 1-800-940-8924 to order Tekonsha custom fit vehicle wiring part number 118386 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.
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  • Reviews (66)
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Tekonsha Custom Fit Vehicle Wiring - 118386

  • 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 - no cutting, splicing or tapping required. Circuit-protected converter guards against shorts.


  • 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 - no cutting or splicing of wires
    • Locate connection points in rear cargo area
    • Plug in T-connector
  • Includes circuit-protected tail light converter to ensure that your vehicle's wiring matches that of your trailer
    • Provides protection against electrical shorts and overloads
  • 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 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 interior trim panels in your rear cargo area.

Once installation is complete, the 4-way flat connector will be stowed in an out-of-the-way location within your 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.

Circuit-Protected Tail Light Converter

A tail light converter 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. The tail light converter combines 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.

This converter safeguards itself and your vehicle against possible electrical shorts and overloads with integrated short circuit protection. Just install the connector as indicated and rest assured that the wiring system of your vehicle will remain feedback-free.

118386 Tow Ready T-1 T-Connector - 4 Wire

Installation Details 118386 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 - 118386

Average Customer Rating:  4.8 out of 5 stars   (66 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 - no cutting, splicing or tapping required. Circuit-protected converter guards against shorts.

2006 Toyota Matrix

Easier to install than I though 2006 Toyota Matrix XR.
Didn't have to jack it up to install.
Also installed the T-One wiring harness only tool needed is a drill with a Philips #2.

Had to remove the lower trim in the back but it looks like it won't be missed. bolts for it are 10mm.


No tools needed to get to the car wiring

The T-One wiring harness only tool needed is a drill with a Philips #2 for the ground screw

2006 Toyota Matrix

Easy to install with clear instructions. Did not even have to drill a hole for the ground, just attached it to a screw from the headlights that went through the metal.

2006 Toyota Matrix XR

Mark S.


Wiring harness still works. Used it many, many times and still no failures. Great product. I recommend etrailer over UHaul any day.Note: I attached it to a screw from the brake light housing, not the headlight.

2008 Toyota Matrix

Worked as advertised.

instructions were understandable and easily followed.

I have ordered and installed a hitch and 2 different harness systems from for similar vehicles. The hitch fit both, but I needed different wiring harnesses. I've had no problems with either of the wiring harnesses nor the hitch for that matter.


The wiring harness was an easy direct fit, install. Tucked the remaining harness in the spare tire well. Used it many times and have had no issues.



Thanks for the follow up, George. Both the receiver hitch and wiring have been working great! I am very happy with my purchases. Thanks.

2010 Toyota Matrix

The T-One Wiring Harness for my 2005 Toyota Matrix was extremely simple to install. I think it took me all of 10 minutes. The etrailer staff was incredibly helpful from the moment I ordered. The only advice I have that was not included in the instructions for the wiring harness is to run the trailer wire through the floor, underneath the spare tire. I believe the instructions show the harness simply coming out of the hatch and then the hatch closing on the wiring. I found round, black gaskets underneath the spare that can be removed and allow access to run the trailer wire to the hitch. This lends a cleaner look. Thank you etrailer staff.

2005 Toyota Matrix

This was the easiest trailer wiring set up I've ever seen. It was specific to my car, so the connecting was just a matter of unplugging the existing wiring and inserting the adapters. Couldn't be simpler.

2010 Toyota Matrix

the wiring was easy to put on took about 10 min. To put on the trailer hitch I went to the auto store and bought a tap to clean the thirds out that took the longest . after that the hitch bolted up just fine.If you are going to put a trailer hitch on a 2004 Toyota matrix clean the thirds out first it make it easer to do.

2007 Toyota Matrix

I purchased the "T-One" wiring harness for my 2007 Toyotal Matrix. I must admit that I was not 100% sure the harness would be as simple to install as etrailer described. WOW! was I wrong.... It took me longer to clear the trunk out and open the box than it took to install the harness. It took me less than 5 minutes to install. The only thing is I wish the lead to the trailer was a little longer. However, I am 100% satisfied. Highley recomended product and will shop etriler again.


It went on without a hitch (see what I did there). Seriously! Four bolts and run the wiring where it belongs. I did it at night with a headlamp and it worked flawlessly. A year later, it’s still tight and the wiring is solid. Thank you for a seamless and painless experience!


Fits perfectly and shipped fast. Now I can haul my CR250R with a Matrix!

2002 Toyota Echo

How refreshing to have a company deliver, and quickly, just what I asked for! I have a 2002 Toyota Echo, and I had no idea where I could get a hitch from. Well, they had it. Everything I ordered arrived within just a couple of days of me ordering it. All of the merchandise is well made and durable. Everything fit, just as it should, and I got it all completed (the wiring and the installation of the hitch), all within one hour. I am very pleased! Thanks so much!


The wiring harness shipped and was received right on time. The harness itself was to replace an earlier etrailer harness installed 8 years ago. The newer harness had clearer directions and took only a few minutes to install.

2000 Toyota Echo

All is well couldn’t be happier w/hitch and wiring harness! Easy to install and have told others of your products.

2005 Toyota Matrix

I did have this installed by a local shop, but they were impressed by the lower price here that what they could a big margin.

Other products with this (hitch, hitch receiver) were just as good.

2007 Toyota Matrix

The item came in a compact, recyclable box, shipped in a small cardboard box - no wasteful plastic. Designed in USA. Good quality. Instructions are clear and in three languages. Customer service was helpful, kind and informative. Tracking was given that helped pinpoint delivery date and even arrived a day early. Great product value - definitely recommend this company and product.


This is a very high-quality product. The connectors on the wiring mated with the factory connectors perfectly. Everything was solidly constructed, and the plug cover is a nice touch. I chose not to drill the hole for the ground wire. Instead I used a stud through the body panel that was near the left tail light (probably holding the light cluster on). Just a few turns with a 10 mm wrench and I was done. Highly recommended.


I bought this as replacement for the U-Haul installed wiring harness that never worked quite right. This unit is much more substantial, has higher quality connectors, and was a cinch to install. I should have gotten this one the first time around.

2005 Toyota Matrix

VERY easy to install. Simple,easy plugins worked the first time. The hardest part was grounding. Not much space to insert a drill and bit in the access panel. Drain plug in bottom of tire space allowed the plug to hang out for use. I cut the rubber plug and inserted it back around the wire for extra protection.


It was easy to install and it's perfect to hitch a trailer or put a bike rack


I ordered a light kit for my older Toyota. etrailer's website was very easy to navigate. Order process was simple. Order was processed and shipped in record time. I'm very pleased with the complete deal. Video on website was very helpful. When I called with a concern. Response was within a couple hours.. This store has all my future orders. Great prices to boot..



Very knowledgeable customer service; Erica spent about 20 min with me on the phone, explained to me different options applicable to my towing needs and a car I planned to install it on. She offered products that would meet my spending limits and meet my purpose. The product arrived as promised. Great investment for small towing. Installation very easy.


Great harness. Plugs right in. Saves time. Worth the money!



Still working good

2004 Toyota Matrix

Very straight-forward install on our 2004 Matrix XR 4WD... I ran the wire out one of the drain plug holes. Cut a hole in the plug and put silicon around the wire to reseal. The entire install took about 30 min.

2003 Toyota Matrix

Fit well except except for the length of the lead from the left side of the cars harness to the control module. The length didn't leave many options form mounting the module to the car.

Show More Reviews

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

  • Does Trailer Wiring Harness # 118386 Need a Battery Connection on a 2005 Toyota Matrix XR
    Because the T-One Vehicle Wiring Harness with 4 Pole Trailer Connector, # 118386, is a non-powered, T-style connector, you will not have to run a power wire to the vehicle battery. The harness receives power and signals through the tail light wiring on your 2005 Toyota Matrix XR. I have included a link to the installation details for you to view.
    view full answer...
  • Recommended Trailer Hitch and Wiring Harness for 2006 Toyota Matrix
    The trailer hitch I recommend for a 2006 Toyota Matrix is the Draw-Tite Sportframe Trailer Hitch Receiver part # 24812. This hitch offers an easy bolt-on install with no cutting or drilling required. It has a 1-1/4" opening which will work great for towing or hitch mounted accessories like bike racks or cargo carriers. In order to tow you'll also need a trailer wiring harness, the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector part # 118386 is a plug-in fit.
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  • Parts Needed to Tow Trailer with 2007 Toyota Matrix
    I took a look at the online version of the owner's manual for your 2007 Toyota Matrix and found that it can tow a trailer that weighs up to 1,500 pounds. I do recommend verifying this in your copy of the manual just in case you have a different model. In order to tow a trailer you will need to start with a trailer hitch. I recommend the Draw-Tite Class I Sport Frame Receiver Hitch # 24812. This custom hitch will use existing holes in your vehicle's frame for a no-drill installation and...
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  • Trailer Hitch For A 2007 Toyota Matrix
    We have the perfect trailer hitch that will fit your 2007 Toyota Matrix! The Curt Trailer Hitch Receiver # C12013 has a shipping weight of 18 pounds. The hitch has a bolt-on installation with no welding required. It has a gloss black powder coat finish that is over a protective base coat that offers superior rust resistance. The trailer hitch has a maximum gross trailer weight up to 2,500 pounds and has a maximum tongue weight up to 250 pounds. I would recommend checking your vehicle's...
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  • Is Trimming of the Vehicle Required When Installing a Trailer Hitch on a 2008 Toyota Matrix
    The only trimming or modification required is if your 2008 Toyota Matrix is an XR or XRS model. The installation instructions for Curt Trailer Hitch, # 12221, linked below, state that if you do have an XR or XRS model, the lower valance MAY require trimming. All of the available trailer hitches have similar disclaimers; that trimming MAY be required. If you plan on doing some towing, the trailer hitch comes with the required ball mount. You can use hitch ball # 19256 (1-7/8 inch diameter)...
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  • Will the Draw-Tite Class I Trailer Hitch # 24812 Fit the 2004 Toyota Matrix XRS
    Yes, the Draw-Tite Class 1 Trailer Hitch, item # 24812, will fit your 2004 Toyota Matrix XRS. The rear fascia on your car has a center section that will have to be removed to install the hitch. The fascia will not be reinstalled. Some items you may need to complete your towing set up, with these hitches, are listed below. Drawbar # 3593 Hitch Ball # 19256 or # 19258 Hitch Lock # 5200 Wiring # 118386
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  • Trailer Hitch Receiver, Wiring, and Cargo Carrier for a 2003 Toyota Matrix XR
    If you use Draw-Tite trailer hitch # 24812 the center fascia (which is a fancy word for the lower plastic bumper part on your 2003 Toyota Matrix XR) will not have to be removed. I have included a link to the installation instructions for you. There is no mention of having to remove the center fascia. The installation video for the 2009 model year is a different hitch design and it will not be exactly the same but pretty close. For a ball mount use # 3593. For a 1-7/8 inch ball use # 19256...
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  • Which Ball Mount Goes with Curt Trailer Hitch for a 2006 Toyota Matrix
    The draw bar or ball mount recommended for Curt trailer hitch # C12013 is ball mount # C45521. For a 1-7/8 inch ball use # 19257 and for a 2 inch ball use # 19258. Then for a pin and clip use # F-4. And for trailer wiring you can use # 118386 to add a 4-Way flat connector to the rear of your 2006 Toyota Matrix. I have linked a video review of the wiring harness for you.
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  • What is the Ground Clearance on Curt Trailer Hitch C12013 on a 2008 Toyota Matrix
    I spoke with my contact at Curt and the measurement from where the hitch mounts to the frame down to the top of the receiver is 6.69 inches on Curt trailer hitch # C12013. From the top of the receiver to the bottom is 1-3/4 inches. I have included a picture a customer submitted showing the hitch installed to give you a better idea of where it will be on the vehicle. I have also included a link to the installation instructions for you to view. If you are planning on doing some towing the...
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  • Difference Between Trailer Hitches C12221 & C12013 On 2007 Toyota Matrix
    Yes, you are correct the differences are that on # C12221 the heat shield modification may be required, and lower fascia may need to be trimmed for hitch installation. On the # C12013 a heat shield modification may be required. It does not need a fascia modification, which presents an easier install on the 2007 Toyota Matrix. Also the # C12013 fits the 2003 - 2008 Toyota Matrix XR and XRS. The # C12221 fits Canadian models of the Matrix FROM 2009 - 2013 (Toyota Matrix,) and 2003 -...
    view full answer...
  • Will Curt Trailer Hitch Receiver # C11289 Fit a 2001 Toyota Echo
    You're correct the reviews are for later models but the Curt trailer hitch receiver, part # C11289, does fit the 2001 Toyota Echo. It's a 1-1/4 inch, Class I trailer hitch that bolts on with no drilling. I've linked the install details for you to take a look at. If you're going to be towing a trailer with your Echo you also need the recommended ball mount, part # C45521, with either a 2 inch hitch ball, part # A-82, or a 1-7/8 inch ball, part # A-80. Then use # F-4 for a pin and clip. To...
    view full answer...
  • Recommended Trailer Hitch For 2004 Toyota Matrix
    The trailer hitch I recommend for your 2004 Matrix is the Curt, part # C12221. This is a Class ll hitch and it has a 1-1/4 inch receiver opening. Per Curt all non-trailer loads - bike racks, cargo carriers and so forth - should be supported with stabilizing straps like part # 18050. Failure to properly support these loads will void your hitch warranty from Curt. I have attached a helpful article that explains how you can clean the rusty weld nuts on your vehicle. You can use something...
    view full answer...
  • Trailer Hitch and Wiring for a 2005 Toyota Matrix
    Curt trailer hitch # C12221 would be a good option as long as your 2005 Toyota Matrix is not an XR or XRS model. If it is an XR or XRS model then # C12013 would be the best option for a Curt hitch. These are both Class II hitches which means you have to use the ball mount recommended by the hitch manufacture so as not to void the hitch warranty. This will limit the amount of rise you can get to be able to tow the trailer level. Based on the picture you have sent you will need a good amount...
    view full answer...
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Info for this part was:

Employee Michael H
Expert Research:
Michael H
Employee Jeff D
Installed by:
Jeff D
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

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