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  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 # 118438
Our Price: $43.68
You Save: 30%
Custom Fit Vehicle Wiring

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118438 - 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 - no cutting, splicing or tapping required. Powered ModuLite reduces strain on wiring system. 1-800-940-8924 to order Tekonsha custom fit vehicle wiring part number 118438 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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Tekonsha Custom Fit Vehicle Wiring - 118438

  • 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 - no cutting, splicing or tapping required. 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 - no cutting or splicing of wires
    • Locate connection point in rear cargo area
    • Plug in connector
  • 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: 4.2 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 passenger's-side interior trim panel in your rear cargo area. Once you've plugged in the connector, insert the included fuse into your fuse panel as indicated in the instructions.

Once installation is complete, the 4-way flat connector will be stowed in the jack storage compartment of your rear cargo area.

It is recommended that you use a small amount of grease on all electrical connections - the plug 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.

118438 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite

Installation Details 118438 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 - 118438

Average Customer Rating:  4.9 out of 5 stars   (524 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. Powered ModuLite reduces strain on wiring system.


I left a detailed review for the Hidden Hitch with THIS product as part of the review because I bought it as a package deal. I will say a quick note on this product alone just for customers information. This was ridiculously easy to install. It literally just PLUGS IN to a control board, then you have to remove a small bolt and attack ground wire, zip tie the wires across to the jack compartment for easy storage when not in use and plug in a small fuse up front. I can honestly say that even someone that is not mechanically inclined or used to working on cars could EASILY install this wiring harness. A great product, great customer service. I give it 5 stars. Highly recommend this product and

Adam P.


Havent used the wires in over a year after our move across the USA. Just towed a boat this late week and the wires all still worked perfect. Had no issues and they were in the same shape as when I first opened the box. High quality product, highly recommend.


Easy to install, fit factory harness

2008 Honda Odyssey

Instructions were well written, and the installation was simple to do.



The harness worked great while we had the vehicle, just got rid of it.


Item arrived intact and was straightforward to install. It seems to be working properly so far. We did see this product at cheaper price on another website but E-Trailer seems to have very good customer service.



So far, so good. We only use this product and the trailer during the summer months. Last summer it worked fine with no issues. We hope that it will continue to work properly this coming summer.

2010 Honda Odyssey

This wiring harness was super easy to install on my 2010 Honda Odyssey. Finding the right part was also a breeze thanks to They made it super easy to locate the correct part.

2008 Honda Odyssey

Package was slightly opened on the side. Don’t know if someone from the delivery company was tryin to take a look on what it was or ripped open during delivery. When I opened the package it was scratched as if it was dragged on one side on a rough concrete floor.. but I guess looks don’t matter or minor blemishes on a piece of metal thats meant to haul... but maybe it’s just me. If I get something new I want to be the one to scratch it on my own. When I hear new. I think undamaged. As far as quality/install it is beefy and easy... I was able to do it solo but used jack stands to hold it in place for me. Wiring was also a breeze except for the fact that the video said to use a self tapping screw to ground the wire. I was expecting a screw included in the small ziploc bag that came with the lock ties and fuse... but other then that install was also easy. I would definitely recommend this company for its product for its price. Just minor issues that is no big deal to me. I gave you a 4 star cause there is always room for improvement.


Excellent attention to detail all the way down to the sticker to add inside the fuse box. Excellent instructional video.

by: 01/22/2024

Good value for the money

2007 Honda Odyssey

You saved the day!! Thank you so much.


Absolutely perfect! Ordering, receiving and installation were absolutely flawless! Thank you!

2008 Honda Odyssey

I've ordered both their low profile hidden bumper and now the light kit for my 2008 Honda Odyssey...both products are "very" easy to install and work Great! Everything I've ordered arrived to my home in days. I would Highly recommend E-TRAILER and their will not be disappointed!!


This was just what I needed to wire my Honda Odyssey van to pull my trailer. It was a relatively easy self-install. Came with a fuse. I just had to pull the back interior panel and it was plug-and-play. Then tucked the wiring and voila - my popup camper has lights and is street legal. Very easy experience with etrailer. Highlander recommended!


Great quality and easy instructions will illustrations.


Was very EZ to install and with clear i nstructions.


Great installation. No more hunting for the correct wiring to make a splice. Good instructions and good videos.

2008 Honda Odyssey

Super easy install. The video was helpful to show how easy it was. Works great!

2006 Honda Odyssey

Overall, a very simple process to install in a 2006 Honda Odyssey EX-L - however, I'm having difficulty locating a way to feed the wiring thru the Jack storage area, and out to the bottom of the van (can't find the grommet some other reviewers used) so that I can permanently hookup my wiring on the outside of the van and fed to the trailer hitch.

I'm not a big fan of storing the wiring inside the Jack Storage area, then feeding the wiring harness out thru the tailgate every time I want to use the wiring harness. I was easily able to find a suitable grommet that I fed the wiring harness thru when I owned a 2003 Honda Odyssey - looks like the 2006 has made some design changes in the rear end. I'll keep looking once my arthritic knee allows me to bend my knees.

Ken R.


Update to my earlier comment posted on 0813/2013. This is a follow on post for a 2006 Honda Odyssey EX-L. I located two easily accessible holes protected by a grommet that leads directly to the bottom of the van - these two grommets are located at the bottom of the storage area beneath the carpeting where the 3rd Row Seats are stored. -Simply lift the 3rd Row Seats if stored into the seating position. -Remove the rear tailgate trim piece same one you had to remove when you first installed the wiring harness.-Lift up on the carpeting that covers the bottom of the storage area for the 3rd Row Seats.-You should be able to see the two grommets left and right at the bottom of the storage area - lift up the grommet location you want to use I used the right one - same side where the wiring harness connects to the van. As soon as you lift out the grommet, you will see daylight!-I cut off the 4 pin connector to be able to feed the wiring thru this hole - you might be able to muscle the connector thru the hole if you push hard enough and will probably have to bend the 4 pin connector thru the hole - youre call. I then had to solder the two pieces back together - pretty simple process if you own a soldering iron and know how to solder. Only issue I saw with this location is to watch the wire sag - this hole location does not offer much protection for the wiring from any potential snag issues while driving if there is too much sagging in the wire. I screwed in 3 conduit-type wire clamps to make sure my wiring does not sag.At some point in the future, I may decide to just drill a new hole on the SIDE as opposed to using the existing BOTTOM hole of this storage area this storage area for the 3rd Row Seating appears to just be a fiberglass and/or plastic resin-type pan that looks like it would be very easy to drill thru - I can then go buy a suitable size grommet to cover the hole.



I used a grommet hole for the factory panel clip. Drilled it out with a 3/8 bit about 4 holes wide.. Then fed the wire through the hole.

2006 Honda Odyssey

I have a honda odyssey 2006, and this product is great a really easy installation, and seem a very good quality

2009 Honda Odyssey

It is fairly easily to install with the instructions provided. So far, so good...

2007 Honda Odyssey

I installed the hitch receiver and wiring harness without any issues, and both work well. I found the video instruction to be much more helpful than the written instructions that came with the products. I needed two new tools: a torque wrench for tightening bolts on the hitch receiver, and a trim removal tool to open the side plastic panel to install the wiring harness.

Edwin H.


Hitch and wiring still working just fine I would say without a hitch, but that would just be confusing...

Honda Odyssey

This is a great wiring kit. It is awesome that the Odyssey has a junction box that thus just clips into. The only tricky part is pulling the passenger rear panel and the threshold panel and that isn't to bad either. The only tools needed for this Odyssey wiring harness is a 10mm wrench for the ground terminal and a body panel pry lever. The instructions and pictures are clear as is the nice video. Anybody who wants to can install this harness without a problem with the clear instructions.

Easy I.


Thanks for the follow up. The hitch and wiring harness have worked great for the last year. Still five-star!

2010 Honda Odyssey

Ordered a hitch for Honda Odyssey. Received it 2 days ago, installed yesterday - easily, with the help from a friend. Everything fit just right, no drilling. The electrical part was no problem. Today used it to tow my boat in for service.

Etrailer was great. Minutes after I placed the order I received an email acknowledging the order and offering to call with any questions. An hour or so later, another email informed me that it has been shipped. Excellent job. Thanks!

A. S.


A year later, everything works fine. Highly recommended. Good product, fine company. Still 5 stars.

2007 Honda Odyssey

I got a hitch receiver and electrical hook up for a 2007 Honda Odyssey.
Ordering was easy.
Asked one question (e-mail). Got my answer the next day.
Hitch installed in 52 minutes, exactly like instructions.
Hitch had 6 bolt attachment. Others brands I looked at only had 5.
Electrical unit installed in about 27 minutes.
Super happy with the whole process.

Jack D.


The wiring harness is still working just fine. NO PROBLEMS.

Patrick B.


Good to know, thanks for checking in.

Honda Odyssey

Honda OdysseyPhotos of trailer wiring installation


This is the second hitch receiver I bought from etrailer

Show More Reviews

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

  • Wiring Problem 2006 Honda Odyssey
    Are you meaning that the running lights work, but not the brake lights or turn signals? Try using a circuit tester on the 4 pole connector, as each function is activated. If all this checks out, the problem is on the trailer somewhere. If you don't get a signal for the turn or brake lights, I'm thinking that the converter might have shorted out when the pole broke. Use a circuit tester to test each function on the INPUT side of the converter box. If you have signal going in, but none...
    view full answer...
  • Troubleshooting Trailer Lights that Come on as Soon as Connecting 2006 Honda Odyssey to Trailer
    Most likely there is a short somewhere that is causing the trailer lights to come on as soon as you connect the harness on your 2006 Honda Odyssey to the trailer. A short will cause constant power draw and will explain why this is happening. I recommend checking both the vehicle and trailer side connectors for any debris, corrosion or damage. You will also want to check the wiring from front to back and look for any frayed, pinched or damaged wire that may be causing the short and repair...
    view full answer...
  • Trailer Wiring Recommendation for a 2005 Honda Odyssey
    For trailer wiring for your 2005 Honda Odyssey you would need the Tow Ready Harness part # 118438 as it has been confirmed as a fit for your 2005 Honda Odyssey. I attached an install video for you to check out as well. This harness does have a converter box to take the taillight signals of your vehicle and convert them into standard 4-way trailer wiring. But the unit itself basically just plugs right into your vehicle for a very easy install.
    view full answer...
  • Troubleshooting T-One 4-Pole Harness 118438 Installation in 2006 Honda Odyssey
    Tekonsha 4-pole trailer wiring harness # 118438 is a correct fit for your 2006 Honda Odyssey and I am sorry you're having an issue with its operation. For reference, I linked the instructions and an installation video showing this item installed in a 2006 Odyssey like yours. Since none of your trailer lights function I suspect either a bad ground connection or that the included fuse is bad or is not installed all the way in the receptacle or is in the wrong receptacle. Please refer to...
    view full answer...
  • 2003 Honda Odyssey EX Trailer Wiring Recommendation
    The T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118438 is not a fit for your 2003 Honda Odyssey. Instead you will want the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118336. This will connect to factory wiring behind the trim panel in the cargo area on the driver's side. A tail light converter is built into this harness so you will have proper trailer function and will not affect the tail lights on your Odyssey. I've attached an...
    view full answer...
  • Trailer Wiring Recommendation for a 2005 Honda Odyssey
    Yes, the Tow Ready Trailer Wiring Kit part # 118438 is a confirmed fit for your 2005 Honda Odyssey and it comes with everything you would need to install the kit on your vehicle and provide you with a 4-way. I attached an install video for this kit for you to check out as well.
    view full answer...
  • Installing the Fuse From T-One Harness Part # 118438 on a 2008 Honda Odyssey EX
    The fuse compartment can be found on the passenger side kick panel, near the glove box. Open fuse compartment and place the 7.5 amp fuse into the position #5. Attach the fuse label to fuse cover in position #5. The instructions are also accessible on our web site at the link below.
    view full answer...
  • Where Does the Fuse Install From Tow Ready T-One Wiring Harness # 118438 on 2005 Honda Odyssey
    Sounds like you are looking at position #5 on the drivers side fuse box of your 2005 Honda Odyssey Touring. When installing the Tow Ready T-One Wiring Harness, part # 118438, on your Odyssey you will want to locate the fuse compartment on the passenger side kick panel, near the glove box. Open the fuse compartment and place the provided 7.5 amp fuse into fuse position #5 in the fuse box. Attach the fuse label to fuse cover in position #5. I am including a link to the installation instructions...
    view full answer...
  • 4-Pole Trailer Connector for 2010 Honda Odyssey
    The Tow Ready # 118438 would indeed be the correct 4-pole trailer wiring harness for your 2010 Honda Odyssey. If you click the provided video, you can see the full installation of the wiring harness on a 2010 Odyssey. I've also linked you to the instructions for the wiring harness. I've also linked you to a listing of the other vehicle specific accessories and equipment offered for your Odyssey.
    view full answer...
  • Trailer Lights Not Working when Connected to 2008 Honda Odyssey
    Not all trailer wiring harnesses are created equal. By that I mean that if there is a weak ground on the trailer side it could work with some but not all vehicles. Also depending on how many lights the trailer has it is possible that it is overdrawing harness # 118438 on your 2008 Honda Odyssey. This particular harness is rated for 2.1 amps per circuit for brake and turn signal lights and 4.2 amps for the running lights. Also you will want to make sure that the wiring harness white ground...
    view full answer...
  • Can the 4-Way Trailer Wiring Harness be Routed Permanently to the Outside of a 2007 Honda Odyssey
    What you can do on your 2007 Honda Odyssey is try to find a grommet at the bottom most part of the cargo area in the back. You will most likely have to remove trim panels and flooring to get to the bare metal of the storage area. The bottom of the jack storage compartment or the spare tire well are good places to look for a grommet. If there is a grommet then you can cut a slit in it and run the 4-Way end through (though you may have to cut the 4-Way end wiring in half and splice it back...
    view full answer...
  • Tekonsha 4-Pole Trailer Wiring Harness for 2004 Honda Odyssey
    The correct Tekonsha trailer wiring harness for your 2004 Honda Odyssey is part # 118336. To assist you I linked an installation video showing your same model year Odyssey. The part you have # 118438 fits 2005 through 2010 model years of the Odyssey.
    view full answer...
  • Trailer Brake and Turn Signal Lights Do Not Work When Running Lights are Turned On
    It sounds like there is either a ground problem or the power draw is too much for the wiring system on the vehicle when the running lights are on. First, check the main grounds on the vehicle wiring harness and the trailer connector. All grounds should be attached to clean and corrosion free bare metal surfaces. Check the trailer connectors on both sides for dirt and corrosion and clean them out. Next check the lights themselves. Many trailer lights ground through the mounting studs if...
    view full answer...
  • How Long Would Install For Trailer Hitch and Wiring for 2007 Honda Odyssey Take
    Draw Tite states that an average install for their hitch part # 75270 that is a fit for your 2007 Honda Odyssey is going to be right at 30 minutes. So if you were to pay a shop it would be 1/2 a shop hour. The trailer wiring part # 118438 that is a fit for your vehicle too would only take a couple of minutes as well. They might have a minimum rate for even messing with it. But I attached an install video to show you how easy it is.
    view full answer...
  • Would Class II Hitch for 2007 Honda Odyssey Be Able to Tow Small Trailer
    The Class II hitches for your 2007 Honda Odyssey like the Draw Tite part # 36417 which is a confirmed fit have a decent towing capacity of 3,500 lbs total trailer weight and 300 lbs tongue weight. If the weight of your trailer is under those figures the hitch would be just fine. You'd also need to check the owners manual of your vehicle to determine the capacities of it as well. Be sure to stay under the lower of the two capacities. For trailer wiring you'd then want the Tekonsha kit...
    view full answer...
  • Trailer Wiring Recommendation for a 2012 Honda Odyssey
    For your 2012 Honda Odyssey I have a solution for you, but the part # 118438 is not confirmed as a fit as it stopped fitting the Honda Odyssey after 2010. Instead for trailer wiring you would need the part # 118521.
    view full answer...
  • How to Test Converter Box of Trailer Wiring Harness
    The first problem is you bought the harness from Amazon and not us...just kidding! What you will want to do is test the wires going into the box of the converter box for voltage with a circuit tester like the # PTW2993 to see if there is voltage going into the box when the taillight functions of your vehicle are applied, and then test the output side of the box to see if the current is making it through the converter. If not then the problem is that the converter box has shorted itself...
    view full answer...
  • Trailer Hitch and Wiring Recommendation for 2006 Honda Odyssey
    On a low sitting vehicle like your 2006 Honda Odyssey trailer hitches are going to reduce ground clearance since they have to hang below the rear bumper. The Draw Tite part # 75270 is a confirmed fit, tucks right up under the rear bumper and would be great for towing or bike rack. For trailer wiring you then would want the part # 118438 which is a confirmed fit and is the 4-way style of harness like you mentioned. If you wanted to do some towing you might be interested in etrailer ball...
    view full answer...
  • Curt Trailer Wiring Harness for 2006 Honda Odyssey has Constant Power
    Are the lights on the trailer actually lighting up or just the circuit tester? If the trailer has LED lights then it is more likely that Curt harness # C56161 will cause them to dimly light up. Curt trailer wiring harnesses that are powered like this one sometimes have this issue. The converter is working properly but for some reason a little power bleeds through causing this exact issue. The Tow Ready harness # 118438 does not have a history of this issue and would be the preferred wiring...
    view full answer...
  • Trailer Wiring Harness for 2006 Honda Odyssey
    From the looks of the photo you sent in, you may have the wrong trailer wiring harness for your 2006 Honda Odyssey. I was unable to find your order number, but the wiring harnesses that fit an '06 Odyssey do not have the extra plug/cap like you are showing. That said, from the photo it looks like that is just a cap for the plug, but that would be unusual because there's really no reason to have a cap on the T-connector like that. The wiring harnesses that fit your 2006 Honda Odyssey are...
    view full answer...
    Image 1 for
  • Install Video Availability of the Curt Wiring Harness part C56161 on a 2010 Honda Odyssey
    I can provide you with a video of different brand's wiring harness that will install the exact same as the Curt Custom Fit Vehicle Wiring # C56161 that you referenced. The video I attached shows the Tow Ready Wiring Harness # 118438 being installed on a 2010 Honda Odyssey just like yours.
    view full answer...
  • Right/Stop Function Stays on After Installing the Tekonsha T-One # 118438 on a 2007 Honda Odyssey
    If you installed the Tekonsha T-One # 118438 correctly on your 2007 Honda Odyssey (see attached video) then the right turn/stop function on your trailer should not always be on. There are a few things that could be causing this issue; there is an insufficient ground on the trailer or vehicle, or the harness has been overloaded. If you had a powered converted with a lead running to the battery then you could remove the fuse from the power line to reset it, but you do not have a powered...
    view full answer...
  • Testing Converter Box of Tekonsha Trailer Wiring Kit part # 118438
    What you will want to do is test the wires going into the box of the converter box for voltage with a circuit tester like the # PTW2993 to see if there is voltage going into the box when the taillight functions of your vehicle are applied, and then test the output side of the box to see if the current is making it through the converter. If not then the problem is that the converter box has shorted itself out and would need to be replaced. Before you replace it you will want to inspect...
    view full answer...
  • Recommended Trailer Hitch Receiver For 2010 Honda Odyssey
    On your 2010 Honda Odyssey all the trailer hitch receiver options will be noticeable from the back as even the crosstube is exposed. I recommend the Draw-Tite Trailer Hitch Receiver - Custom Fit - Class II - 1-1/4" # 36417 which is the least noticeable based on size. This is your best option for being discreet. The Draw-Tite Max-Frame Trailer Hitch Receiver - Custom Fit - Class III - 2" # 75270 will give you more options for accessories and greater strength while being a little more...
    view full answer...

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Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Patrick B
Expert Research:
Patrick B
Employee Michael H
Expert Research:
Michael H
Employee Jeff D
Expert Research:
Jeff D
Employee Reno H
Expert Research:
Reno H
Employee Jameson C
Expert Research:
Jameson C
Employee Adam R
Expert Research:
Adam R
Employee Zack K
Video Edited:
Zack K
Employee Joshua S
Video Edited:
Joshua S
Employee Patrick B
Video Edited:
Patrick B
Employee Chris R
Video Edited:
Chris R
Employee Nicholas E
Test Fit:
Nicholas E
Employee Kathleen M
Video by:
Kathleen M
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

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