T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
(239 reviews)
Price: $81.28
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
Retail:$91.52
Our Price: $81.28
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Tekonsha Custom Fit Vehicle Wiring
- 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.
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 tail lights
- 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: 2.1 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 driver's-side and passenger's-side tail lights. You will have to remove the tail light assemblies to access this harness. 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 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 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.
118648 Tow Ready T-1 T-Connector - 4 Wire - Modu-Lite
Item # 118648
Installation Details
This Product Fits The Following Vehicles
- 2015 - 2020 Toyota Sienna
- 2015 - 2020 Toyota Sienna excluding SE
California residents: click here
Customer Satisfaction Score:
97% were satisfied with this product
3% of customers were not satisfied
- Wrong item was ordered
- etrailer mistake
- Alternate product found
Customer Reviews
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 118648
Average Customer Rating: 4.7 out of 5 stars (239 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: Daniel10/28/2022
This worked out great! I absolutely love that they provide a video of how to install it and shows what you need, need to do, and what you'll run into. I had to get creative in making sure the wire that runs from the back to the engine battery was going along a good path that might not get road damage. The rear lights were easy to come off and connect to. The interior panel was easy to take off as well to run the wire underneath. I like that the wire is stored away in the panel door and gets pulled out only when needed to be used because it easily hangs out the back door without any issue.
by: Scott05/12/2023
I have not had a moment to install my hitch and harness, however as with many others apparently, the box arrived opened and the hitch had ZERO packing materials...just a big empty box for the hitch to bounce around. I do see some scrapes and scratches, but nothing that I would return it for. etrailer would be wise to review the comment section and revise how they send their product.
by: Justin 02/20/2023
2017 Toyota Sienna
The kit is perfect, came with everything I needed plus some. The only thing I did different was instead of running a new line back to the battery, I jumped off to the cigarette lighter right next to the rear compartment and put a 1 amp fuse on. My lights are LED so the draw is nothing. Saved a lot of time having to run that wire.
by: Disappointed10/06/2022
2018 Toyota Sienna XLE. The wiring harness blows my fuse or other wise makes my turn signals not function properly; I've tried connecting them four times and they keep malfunctioning. So I have to keep them disconnected at the tail light assembly. The brake lights work fine.
Comments
Is this occurring with a trailer plugged in? There could possibly be a short in your trailer wiring causing fuses to blow. Ill link to a troubleshooting article that will provide some direction for you. If this occurs when the trailer isnt plugged in, you might have a faulty harness that needs replacement. If thats the case, get back with us and well help further.
-- 
Mike L - 10/12/2022by: Paul07/09/2019
2019 Toyota Sienna
Installation of the hitch, wiring,rear bike rack, and new roof rack towers went well. I didn't set any speed records, but I was more concerned with doing no damage on a new 2019 Toyota Sienna AWD van. The hitch fit up well per instructions except that I was able to work around the exhaust without lowering it. Underbody panel and rear fascia did both need to be removed. Very happy with the end result. The new van is now set up to haul the bikes and canoes and move my log splitter.
by: Dorian04/20/2023
The installer was very impressed with the product we chose. Thank you!
by: Chris M05/10/2017
2015 Toyota Sienna
Very easy to install. Total wiring time = 45 min. I did not take apart the rear panel by the driver side taillight to run the wire harness. It was a little difficult to fish through due to the size of the connections.
by: Greg06/04/2021
Quality and fitment of products was excellent. Highly recommend install videos on etrailer. The shipping time was very slow. I had some items price matched and that delayed processing a week or more.I provided all links to competitor's products. Very close to month before I received product (it was in stock). That is why I didn't give it an excellent rating.
by: Chris10/26/2021
2020 Toyota Sienna
I guess the packing method is "throw it in a box and hope it gets there. Hopefully etrailer packaging/shipping sees this review and can add the $3 in styrofoam to protect the hitch from going through the box.
by: Mark07/14/2023
Excellent hitch, fits flush under the number, about 2 hours to install!
by: Dirk08/17/2022
The hitch and wiring harness are already installed and work just fine. The shipping timing was fine, BUT the hitch moved around quite a lot in the box as it was not padded, and created a hole in the box big enough that the harness kit could have fallen out of the box.
by: Dean08/10/2019
2019 Toyota Sienna
Install was easy, I watched the instruction video about 3 times and kept it up on my phone to verify my connections when it was time. I had the job complete including all cleanup and mounting the electrical connection to the hitch in about 2/12 hours. I took my time to verify no damage was done to our new sienna.
by: Jeff 07/05/2022
Toyota Sienna
The T-One Vehicle Wiring harness was easy to install. The video was very helpful, but it could use a description of how to run the power line up to the battery. I ran mine (2020 Toyota Sienna XLE) on the inside of the vehicle until I got to the fire wall then went out through a rubber grommet above the accelerator and brake pedal. I used a trim tool kit to move trim pieces enough to slip the wire under the trim.
by: Karl01/18/2023
Fit perfectly, one man install, paint holding up fine, the reciever is properly sized. Would highly recommend.
by: Rob07/23/2018
2018 Toyota Sienna
Easy installation in the jack storage area. Found a open spot to run power wire throught a harnes grommet so I could run power back to the converter inside and under trim
by: Cha Lee08/24/2022
Does not work as stated. Brake tighrs on trailer stays on even when the brake is not press on. ??
Comments
You mentioned that the brake light stays on when the brakes are not being pressed. I would like to help and I have a few questions to ask. Is the brake light brightly lit or is it dimly lit? If you have LED lights, then they may remain on dimly whenever trailer is connected to vehicle. It is recommended to disconnect trailer when parked for extended periods. If it is brightly lit, then it could be that the harness has been overloaded or that there is an insufficient ground or short to ground on trailer or vehicle side. I recommend taking a look at the FAQ that I have listed below. It will provide ways to test the harness and also possible solutions.
-- Jenny N - 09/07/2022Troubleshooting 4 and 5-Way Wiring Installations
![Troubleshooting 4 and 5-Way Wiring Installations]()
by: Brian05/20/2020
2015 Toyota Sienna
Works well. I ran it through the interior of the car instead of under the chassis. Since I don't have a lift; that was a better option.
by: Adam05/03/2022
Toyota Sienna
This wiring kit made the process of getting trailer lighting installed in my Sienna as easy as it could be, since Toyota does not have a factory harness available. The instructions were clear, though it would have been nice if they were in color. All in all, I was able to follow the instructions and get the kit installed in about the amount of time they specify. Works great!
by: John03/09/2023
Kit fit great , all parts work perfectly muffler shield came loose but got fixed thanks
by: Colin S10/06/2017
2016 Toyota Sienna
Superb. I cannot imagine going elsewhere for hitches and accessories. Since I am not too handy I find the videos invaluable as a source of techniques and tips. The kit contained everything necessary for the installation except basic tools. The trailer lights worked first time so what more need be said. I needed the trailer in a hurry but I did not have a way to lift the van so I could only do a temporary job of running the hot lead forward to the battery, with the plan to have my regular auto mechanic redo it correctly asap. You will have to lift the van somehow to do a thorough job of securing that long lead. I wish I had bought dielectric grease, extra double sided tape and extra connectors.
Comments
After one year it still works perfectly and I am fully satisfied. Great product and service from eTrailer.
Colin S - 10/06/2018by: Robert05/17/2022
2018 Toyota Sienna
The T-One 4-pole harness was delivered earlier than expected. Installation was very easy, especially after viewing a video that was quite helpful by demonstrating removal of vehicle trim parts. Installation took me about 4 hours total including collecting tools and clean-up. The longest and most difficult task was running the positive wire along the under-body to the battery, since I did not have my vehicle on a lift. The plug now works and we're ready to tow.
by: Christopher 11/08/2022
2017 Toyota Sienna
The Process on this app was straightforward and I also used the Chat too verify a few questions I had about the products I was purchasing. I don't have any Photos/ Video yet but I assure you New Customers it was easy too navigate this site. US Army Veteran Red Oak Texas
by: David09/04/2018
2017 Toyota Sienna
Easy to install. I did not run a wire up to the battery/fuse block. I installed a cigarette plug on the wire and used the power point near the tailgate. I keep the cigarette plug and trailer plug wires in the jack storage area. I rarely use the trailer lights as my hitch is mostly used for bike racks and a hitch basket.
Shipping was fast.
Comments
Drawing the power directly from the battery serves to isolate the tow vehicles sensitive electronics from any short circuits that might occur in the trailer wiring. Connecting the converters power feed anywhere other than the battery or where the converters manufacturer recommends can leave your vehicles electrical system exposed to possible damage, and will also unfortunately void any warranty coverage.
-- Mike L - 09/05/2018by: A+1204/20/2022
2017 Toyota Sienna
Great kit! The instructional video was awesome, easy to follow, and allowed for a clean install. If you install at the same time you put on the hitch, it is really easy to route the wires while the bottom cover is already off the van/car.
by: Jim 12/16/2020
2019 Toyota Sienna
Got the wiring harness in the mail and got it installed the very same day. Easy to follow instructions and was designed for my vehicle. Was able to pick up the travel trailer the next day after installation.
Comments
Been on several camping trips with our new trailer receiver hitch and wiring harness is installed on a Toyota Sienna and the 2 respond as 1 vehicle. Very satisfied.
Jim M - 12/17/202125
239
Show More Reviews
See what our Experts say about this Tekonsha Custom Fit Vehicle Wiring
- Recommended Trailer Wiring Harness for 2017 Toyota Sienna XLEFor your 2017 Toyota Sienna XLE, I recommend the Tekonsha T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118648. This harness plugs into your Toyota Sienna's wiring harness, which is located behind the driver's-side and passenger's-side tail lights. You will then run the included power wire to your vehicle battery. This will power the harness and protect your vehicle's electronics. I've attached a video of this installation and have attached an article to help with...
view full answer... - Trailer Wiring Harness for 2015 Toyota Sienna XLEFor your 2015 Toyota Sienna XLE you will need the T-One Vehicle Wiring Harness, # 118648. This wiring harness is designed for all models of the 2015 Sienna except the SE. I have included an installation video for you.
view full answer... - Trailer Wiring Harness Recommendation for 2017 Toyota SiennaFor trailer wiring harnesses I prefer the Tekonsha brand as they tend to be more reliable over time. So for your 2017 Toyota Sienna you would want the part # 118648 which is a confirmed fit. I attached an install video for you to check out as well.
view full answer... - Easy Solution for Trailer Wiring Install Harness Installed Backwards 118648If I were in your situation I would do exactly what you described. Just swapping the green and yellow wires on the output side of the converter going to the 4-way will take care of the harness being installed backwards without any negative impact at all.
view full answer... - Can the T-One Vehicle Wiring Harness for a 2017 Toyota Sienna Be Powered Using the Rear 12 Volt AuxThe T-One Vehicle Wiring Harness part # 118648 which is a fit for your 2017 Toyota Sienna will need to be powered directly from the vehicle's battery. If you choose to use the rear 12 volt auxiliary power which is not what I recommend then you will need to do so at your own risk. The maximum amp draw for the above trailer wiring harness is separated between two circuits, 7.5 amps for the tail lights and 2.1 amps for the stop/turn signal lights. I have attached an install video that shows...
view full answer... - Correct Trailer Wiring Harness for 2019 Toyota Sienna LEFor your 2019 Toyota Sienna LE I highly recommend the Tekonsha T-One Wiring Harness # 118648, which will plug right in behind the tail lights. Once you run the power lead up to the battery you'll have a fully functional 4-Way connector to power the camper's signal lights. I have attached a full install video on the 19 Sienna below that you can follow along with too.
view full answer... - Total Amp Rating Of Tekonsha T-One Needed For 4-way Connection To Uhaul 5x9 Utility TrailerThe T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118648 has a maximum amperage of 2.1 amps per circuit for the stop/turn lights and 7.5 amps per circuit for the tail lights. It is designed for a 15 amp fuse, so I can't recommend running the wire to a 10 amp outlet as overloading a circuit could cause a fire. The kit comes with the wire needed for running the 12 gauge wire to the battery and that is my recommendation. It takes a little more work to install but will...
view full answer... - How To Choose Correct Trailer Wiring Harness for a 2017 Toyota SiennaThere are several trailer wiring harness options for a 2017 Toyota Sienna. The first thing you need to do to find the correct one is identify the trim package, if it's an SE then this will further narrow down the selection as there are harnesses specific to this package. The next thing you will need to do is determine what type of trailer connector you need, 4-way is most common but there are also 7-way options for trailers with brakes. With all that in mind, there are multiple options...
view full answer... - Trailer Wiring Harness that Fits 2020 Toyota SiennaYes, the Tekonsha 4-way kit part # 118648 that you referenced is the correct trailer wiring kit for your 2020 Toyota Sienna. This installs by plugging inline with the taillights like you can see in the attached install video.
view full answer... - Install Video to Use for Tekonsha Trailer Wiring Harness on 2017 Toyota SiennaI attached the install video we shot for the Tekonsha trailer wiring harness part # 118648 on a 2017 Toyota Sienna. I would recommend following it as a guide completely and you'll have no issues with the harness and would be installing it in a way that wouldn't void the warranty.
view full answer... - Trailer Wiring Recommendation for 2015 Toyota SiennaThe best trailer wiring install harness for your 2015 Toyota Sienna is the Tekonsha harness part # 118648 which has the easiest install and also has the most reliable converter box.
view full answer... - Which Trailer Wiring Harness Will Work With 2017 Toyota Sienna LEThe difference between part # 118648 and part # 118498 is that part # 118498 is designed for the SE model and part # 118648 is designed to work with Siennas that are not the SE model. Since you came from the non-SE model the trailer wiring harness that will work for you is part # 118648. This trailer harness is a simple installation. You just plug it into the connection points behind the driver and passenger side tail lights and then run the hot lead wire to the positive battery post...
view full answer... - What Trailer Wiring 4-Way Harnesses Fit a 2016 Toyota SiennaIf the 2016 Toyota Sienna happen to be an SE model then yes, the trailer wiring from a 2012 like the part # 118498 would also fit it. If it's not an SE model you would need to go with the part # 118648. I attached install videos for both harnesses as well.
view full answer... - Trailer Hitch and Wiring Recommendation for 2015 Toyota SiennaFor your 2015 Toyota Sienna the Draw Tite hitch part # 75237 would be what you would want. This hitch has plenty of capacity, is priced great and is a confirmed fit for your vehicle. The round crosstube would be it less visible than a square tube hitch as well. I attached an install video for you to check out too. For trailer wiring you would need the part # 118648 which I attached an install video for as well.
view full answer... - Does a 2017 Toyota Sienna Comes With a Factory Trailer Wiring HarnessI do not believe a 2017 Toyota Sienna comes with a factory trailer wiring harness but I do have what you need to add one, the T-One Vehicle Wiring Harness part # 118498 for SE trims or part # 118648 for all other trims. These harnesses are both plug and play options that do not require any splicing. I recommend the T-One Vehicle Wiring Harness in particular because they have the best reputation for longevity and reliability. I have attached an install video for you on both options.
view full answer... - Trailer Wiring T-Connector Compatible with 2018 Toyota Sienna SEFor your 2018 Toyota Sienna SE I recommend the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118498. This is the confirmed fit for the SE model which is slightly different than the other models. It will install in the same way behind the tail light assemblies and with power directly from the vehicle battery to protect your Sienna SE wiring and electronics. I've attached a video to assist as well as an article for help routing that power wire. Once the installation...
view full answer... - Trailer Wiring Recommendation for 2016 Toyota Sienna SEFor the 2016 Toyota Sienna the correct trailer wiring kit depends on if the vehicle is an SE or not. The SE models would require the Tekonsha part # 118498 whereas the non-SE models require the # 118648. It sounds like you have an SE model and ordered the wrong kit. I recommend the Tekonsha brand of trailer wiring because it's our most reliable option we have.
view full answer... - Best Trailer Wiring Harness for a 2018 Toyota SiennaThe best trailer wiring harness we have for your 2018 Toyota Sienna is going to be the T-One Vehicle Wiring Harness part # 118498 if you have the SE model with features such as daytime running lights, 4.2" color multi-information display, and a premium audio system. If you have the LE or XLE then you will want to use the T-One Vehicle Wiring Harness part # 118648. They both install in the same way which requires you to remove the tail light housings, plugging in the t-one connectors, and...
view full answer... - Trailer Hitch for 2020 Toyota Sienna XLE without Tow PackageIf you are looking to have a hitch installed on your 2020 Toyota Sienna that would indicate that you don't have the factory tow package since that would have been included. For a hitch the mostly hidden Draw Tite # 76112 is a really great option that I would recommend highly. Then for trailer wiring the Tekonsha kit part # 118648 is an easy to install and very reliable option as well.
view full answer... - Which Trailer Wiring Harness for 2015 Toyota Sienna XLEIt seems that you have the wrong wiring kit. From the 2015 model year up to the 2021, the Tekonsha # 118498 is only a fit for SE models of the Toyota Sienna which used different taillight assemblies than the other models. For models other than the SE, you'll use # 118648. I've provided a photo showing the differences in the connectors. There isn't an adapter kit, unfortunately. You'll need to install the proper harness kit. I've linked to an install video for the # 118648.
view full answer...
- Trailer Hitch Receiver For 2017 Toyota Sienna XLE With Highest CapacityThe trailer hitch receiver that fits your 2017 Toyota Sienna XLE with the highest capacity is from Draw-Tite, and is the following part number: - Draw-Tite Max-Frame Trailer Hitch Receiver # 75237 This hitch, which fits all models of '17 Sienna, including your XLE with the Premium package, has a towing capacity of 4,500 lbs and tongue weight capacity of 675 lbs, both of which are the highest available for your Sienna. Keep in mind you will still need to abide by the 3,500 lb towing capacity...
view full answer... - Differences in 118648 and 118498 Trailer Taillight Wiring Harnesses for 2017 Toyota SiennaThe difference between the # 118648 and the # 118498 is the taillight assemblies on the SE model are different, they use different connectors. The 2017 Toyota Sienna SE would use the # 118498 while all other models, including your XLE would use the # 118648. If you click the provided link, you can see an install video for the # 118648.
view full answer... - Correct T-One Vehicle Wiring Harness for a 2016 Toyota Sienna L, LE, XLE, or LimitedIf you have a 2016 Toyota Sienna LE then the correct T-One Vehicle Wiring Harness is part # 118648. If you have a 2016 Toyota Sienna SE the the correct T-One Vehicle Wiring Harness is part # 118498. These are both plug-in play options that provide you with a standard four way flat which is the most common. The T-One Vehicle Wiring Harness is part # 118648 also fits any other model expect for SE so if you have an L, LE, XLE, or Limited then this is the correct harness for you.
view full answer... - Trailer Hitch and Wiring Recommendation for 2017 Toyota SiennaFor your 2017 Toyota Sienna the Draw Tite hitch part # 75237 is a confirmed fit and would work well for you. I attached an install video for this hitch for you to check out too. For trailer wiring you then would want the part # 118648 which is a custom fit for your van. Since you wanted to do some towing you might be interested in etrailer ball mount kit # 989900. It comes with 2 ball mounts; one with a 3/4 inch rise or 2 inch drop and one with a 2-3/4 inch rise or 4 inch drop. It also...
view full answer...
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Installed by:
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