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  1. Custom Fit Vehicle Wiring
  2. CURT
  3. Custom Fit
  4. Trailer Hitch Wiring
  5. 4 Flat
  6. No Converter
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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

Our Price: $28.25
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Custom Fit Vehicle Wiring

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CURT 4 Flat Custom Fit Vehicle Wiring - 55540
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Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring - no cutting, splicing or tapping required. 1-636-306-4830 to order CURT custom fit vehicle wiring part number 55540 or order online at Free expert support on all CURT products. Great prices and Fastest Shipping for Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector. Custom Fit Vehicle Wiring reviews from real customers.
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  • Reviews (159)
  • Q & A (0)
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  • Why etrailer?

CURT Custom Fit Vehicle Wiring

  • Custom Fit
  • Trailer Hitch Wiring
  • 4 Flat
  • No Converter
  • CURT

Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring - no cutting, splicing or tapping required.


  • 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
  • Comes with dust cap for 4-way flat connector
  • Limited 1-year warranty


This custom-fit T-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.

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.

55540 CURT T-Connector - 4 Wire

Item # 55540

Installation Details 55540 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 55540

Average Customer Rating:  4.9 out of 5 stars   (159 Customer Reviews)

Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring - no cutting, splicing or tapping required.


I got the same curt T connection again because it's so easy to use and also the bumper mount hitch .again I say it's so easy to install, i did it in less than a hour ,Love it when I use it for my Cargo trailer. Thanks for your support. Also EZ cargo rails and for quick access to tie downs. Thanks Dana for the Ordering.

2015 Chevrolet Express Van

I was very satisfied with the service and and follow up provided by etrailer, the product was exactly what I was expecting and the informative videos provided were superb,thank you so much from a very satisfied customer.l definitely plan to make future purchases from etrailer.

It has been great,l have no complaints or regrets.
Philip - 05/16/2022


Hooked up nicely just want I wanted no spicing of wires from the the factory harness to this one for the trailer.


fit my van perfectly and the quality of the build and finish was excellent


everything good, we use etrailer for all our trailer needs

2009 Chevy Express

Installation on 2009 Chevy Express Van - the installation of this harness couldn't have been easier (especially when you pair it with etrailer's instructional video). The only error I made was on the driver side where there are two connections that will work with this harness. BE SURE TO USE THE UPPER CONNECTION (see attached picture).

2017 Chevrolet Silverado 2500

I purchased this over the other brand because according to the reviews I've read this came with a longer 4 pin wire. I routed through the brake light paneling to get a clean look and had plenty of wire to reach my 7 pin connector. No pigtail coming out of my rear doors. This was installed in a 2017 Chevy Express 2500 passenger van.

2008 Chevrolet Express Van

Unfortunately I have not installed this yet. I’m waiting for the hitch to arrive it’s on back order. I can say your tracking system is not very good. A day before it arrived your system still showed it on the other side of the U. S. But I did get it intact and in damaged. Have a great day.


Exactly the right solution for me. It was easy to install. Videos were helpful. I light up the trailer with no issues. I have no complaints about this product. Price for price, I always prefer etrailer.

Very reliable. No issues. I would buy it again. I am very pleased with his product.
Javier - 06/03/2021

2018 Chevrolet Express Van

Easy to order
Shipped fast
to install. 20 minutes and done.
Easiest I’ve ever installed, and I’ve done a few.
Wiring kit connects inside the van and yet, it appears I have some wires from the factory right down by the hitch. I may test them before I use the wiring kit.


Instructions in the package were virtually useless, the best help was the video on the etrailer website of the installation process for the comparable Tekonsha brand wiring harness. The installation is very simple plug and play once you know where to start.


This is what I expected, thank you. They work great.


Everthing fit perfect no problems .Order came in couple days


Easy to install.


Excellent product and great video for how to install the wiring. The hitch went on my cargo van “without a hitch”! Solid construction.


Quality product and installation was a cinch!


Installed on a 2017 Chevrolet 2500 Express as if it were an OEM part Great to have third party suppliers making parts this easy to install


Easy to follow instructions and worked as advertised.

2013 Chevrolet Express Van


HAROLD P - 03/13/2018


Love etrailer easy to look up also priced very reasonable love this web site easy to find all your trailer needs

2010 Chevrolet Express Van

Product arrived from etrailer and it was exactly as spec'ed. I own a conversion van and getting to the required junctions was a little bit of a pain, but that's not the product's fault. Once the appropriate interior panels were off, the wiring itself took 5 minutes and everything worked perfectly. I was lucky in that I needed to drill no holes. I used the product to help pull a rental trailer with no issues.

Nothings change. Im not a heavy user of the product. It just sits in backuntil I need it. I happy with the review too. Still stands.
Andy - 06/24/2015


It was easy to put together in 5 minutes. Haven't used it yet.

2010 Chevrolet Silverado 1500

My experience with "etrailer" was better than expected. 1)_ The lady over the phone assisted me with my complete product order for my specific towing need for my 2010 Chevy Express 1500 Van. 2)_ I live in So. Cal. and I added the 7.50$ to insure the delivery in (5) working days. I received my package in (3)... So surprised and happy. 3)_ I received a follow up phone call and email confirming the delivery. The CURT hitch and wiring harness worked perfect and the directions we're spot on. To NOTE: My 1500 Chevy Express Passenger Van is hard to fit parts for but *(She/Customer Service) knew exactly what I needed and the follow up was a welcome surprise. I recommend "etrailer" highly. MA6HINE

2013 Chevrolet Express Van

Bought replacement truck in MOORE, OK and ordered hitch and accessories via iPhone in route back to Chicago. Order was there one day after returning and installed the following weekend.
Hitch fit and looks like the OEM option and helpful video made the install a snap... did it in my driveway.
Good price, fast shipping and wide selection makes etrailer a great value.
p.s. I ordered the etrack system for the interior and made cargo containment a pleasure to deal with!


We are a bath remodeling company in the San Francisco Bay Area.
We depend on our work trucks and trailers to get us to and from our work sites, so we can't just make the wrong choices when it comes to having them available 24-7. So this is why we choose to purchase our trailer and truck products from dependable companies like
We ordered the wiring harness and in no time at all, it arrived as promised and right the first time!
Thanks, you all rock!

Show More Reviews

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

  • Trailer Wiring Recommendation for a 2009 Chevy Express Van with or without Tow Package
    The final authority on whether or not a vehicle has a tow package will be a Chevy dealer. If you give them your VIN they will be able to tell you. However, if you do not have trailer wiring on your 2009 Chevy Express there is a very strong chance you do not have the tow package. So then for wiring you would want the # 55540. Also, this will fit models of the Express that do have the tow package as well so either way it will work for you.
    view full answer...
  • Trailer Wiring Harness Recommendation for a 2012 GMC Savana 3500
    Yes, the Trailer Wiring harness part # 55540 that you referenced is a confirmed fit for your 2012 GMC Savana 3500 and will provide you with a 4-way trailer harness. I attached an install video for you to check out as well.
    view full answer...
  • Trailer Wiring Recommendation for a 2008 Chevy Express Van
    Both the trailer wiring harnesses # 31345 and the # 55540 that you referenced have been confirmed to fit your 2008 Chevy Express Van. Both have their pros and cons. The # 31345 only uses the taillight circuits of your vehicle as signal wires and draws all of the power to illuminate your trailer taillights from the vehicle battery. This is a better setup overall that will reduce the risk of over drawing your vehicle's taillight circuits at the cost of a more in-depth install and a little...
    view full answer...
  • Wiring Connection For Passenger Side Curt Vehicle Wiring Harness on 2019 Chevrolet Express 3500 Van
    The 6-pin connector for the passenger side of the Curt T-Connector Vehicle Wiring Harness # 55540 on your 2019 Chevrolet Express is located about 8" higher behind the upper trim panel. You can follow the wiring that comes from the taillight to the correct connector. I have also included a video from the Tekonsha T-One Vehicle Wiring Harness # 118392 that shows the connector a bit more clearly.
    view full answer...
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  • Trailer Wiring Recommendation for a 2013 Chevy Express Van
    What I would recommend you get is a Curt Custom Fit Vehicle Wiring # 55540. This wiring kit plugs inline with the tail lights of your vehicle and will activate the trailer lights of your small trailer. Curt has determined that you do not necessarily need a powered unit like the Hopkins Converters # 46255 or # 46365 and since your trailer only has two lights on it I think the # 55540 would work well for you. The main difference between the # 46255 and the # 46365 is that the # 46365 can...
    view full answer...
  • Is Non-Powered 4-Pole Wiring Harness Safe for Use in 2008 Chevy Express 3500 15-Passenger Van
    For the 2008 Chevy Express 3500 15-passenger van we do have non-powered 4-pole harnesses # 118392 and # 55540 that are intended to add trailer wiring for vans without the tow package. These simply plug in at the two tail light assemblies to get the necessary lighting signals for the trailer and that lighting power is then drawn through the van's own internal wiring. We also have a powered converter harness # 31345 that uses a separate 12V power connection to the van battery. This provides...
    view full answer...
  • Recommended Trailer Wiring Harness for 2001 Chevy Express Van
    I do have a solution for you, however the Curt T-Connector Vehicle Wiring Harness # 55540 referenced in your question is designed to fit the 2003 to present Chevy Express Vans. This wiring harness will not work on your 2001 model. For your 2001 Express Van 3500, I instead recommend the Curt T-Connector Vehicle Wiring Harness # C55377. This is confirmed to fit your vehicle and will install by connecting directly to built-in ports located behind the trim panels in the cargo area on the driver...
    view full answer...
  • Trailer Hitch For A 2021 Chevrolet Express Cargo Van
    Yes, the etrailer Trailer Hitch Receiver # e98861 does in fact fit your 2021 Chevrolet Express cargo van. If you need wiring, we have the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 55540. This is an easy to install wiring harness that plugs directly into your factory wiring harness for quick installation. The reason wiring is needed is, to provide your trailer with turn signals and brake lights, that way you are safe on the road and in legal compliance.
    view full answer...
  • Hitch Recommendation for a 2015 Chevy Express Van
    The Curt Hitch part # C15320 that you referenced has been confirmed to fit your 2015 Chevy Express Van so I would recommend it for you. I attached an install video for you to check out as well. If you plan on doing 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 includes a 1-7/8 inch ball, 2 inch ball, hitch pin with clip, and a storage bag. If...
    view full answer...
  • Why Does 4-way Connector Harness On 2003 Chevrolet Express Van Have Red Wire Grounded?
    Based on the picture you provided it looks like the harness you have was designed for either a 2-wire (combined brake and turn signals) or 3-wire (separate brake and turn signals). Since your 2003 Chevrolet Express Van 3500 has combined wiring you would need to ground the red wire, which is what they have done. You didn't mention what exact issue you are having regarding the taillights on your 2018 Coleman trailer, but I would start with using a circuit tester like # PTW2993 to test each...
    view full answer...
    Image 1 for
  • Will the Hopkins Plug-In Simple 41155 Fit a 2014 Chevy Express
    It sounds like you're looking for the wiring that is used on a 2014 Chevy Express that has the factory tow package wiring, which the Hopkins Plug-In Simple Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector # 41155 is compatible with. The Curt # 55540 is designed for Express vans that don't have the factory tow package, so if your van didn't have the tow package you will need to use this harness. If you also need a hitch to replace the one you took off, the etrailer...
    view full answer...
  • Recommended 7-Way Wiring Harness for 2001 Dodge Van 2500
    In order to get a 7-way connection on your 2001 Dodge Van 2500 without a factory trailer connector you will need to start with a 4-way connection. I recommend the Tekonsha 4-Pole Hardwire Kit with Circuit Tester # 18252. This kit will hardwire into your Dodge van and comes with quick-splice connectors and a circuit tester. Once you install your 4-way you will be able to add the 7-way connection. I recommend the Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way...
    view full answer...
  • Installing A 7-Way Connector On A 2019 GMC Savana 2500 Cargo Can
    The 7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End # HM40975 is designed to plug into a factory 7-pole connector to give you the ability to connect a 4-pole flat and 7-pole round without the need for an adapter so this product would not hook up with the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 55540. Instead you would be able to use the # 55540 with the Universal Installation Kit for Trailer Brake Controller - 7-Way RV and...
    view full answer...
  • Where Do I Connect My 4-Way Wiring Harness On My 2021 Chevrolet Express Van Without Tow Package
    It does not matter which 4-way wiring harness you have. It can be the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, part # 118392, the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, part # 55540, or the Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, part # 31345. They all plug in to your vehicles lights at the same spot. Personally, I am a fan of the Tekonsha T-One wiring harness. If you look at the rear...
    view full answer...
    Image 1 for
  • Best Hitch Receiver for a 2013 Chevrolet Express 1500
    I verified with the manufacturer and they told me there aren't any issues for your AWD 2013 Chevrolet Express Van. Since they're the same, I would suggest the Curt Class V # C15320 to give you the highest towing capacity for your van. With that being said you may also be interested in the T-Connector Vehicle Wiring Harness # 55540 and the Curt Channel Style Adjustable Ball Mount # C45900. There is an installation video of the wiring and reviews of the ball mount attached for you. I...
    view full answer...
  • Recommendation for Wiring 4-Way on 2016 Chevy Express Van for Reverse Lights
    The Curt T-Connector Vehicle Wiring Harness # 55540 referenced in your question, which is confirmed to fit your 2016 Chevy Express Van, does not by itself have a reverse light wire. This harness will provide a 4-Way flat that will power the trailer's basic signal lights. In order to tap into your reverse lights, I recommend simply using the Tow Ready 4 Pole to 5 Pole Adapter # 20036 after you have the above 4-Way installed. This will plug directly into the 4-Way flat to provide you with...
    view full answer...
  • 7-Way and Brake Controller Kit for 2017 Chevy Express 3500
    The kit you mentioned is essentially a t-one style 4-way kit with a 4-way to 7-way kit like the # ETBC7 so to replicate that you'd just want the # 55540 with the # ETBC7 and a brake controller of your choice like the # TK63VR and you'd be set.
    view full answer...
  • Recommendation For Wiring Harness On 2014 Chevrolet Express Van
    You can use a circuit tester like part # PTW2992, to find out what all of the functions are on the connector you have on your 2014 Chevrolet Express Van. If you find it does not have the functions that a trailer would use, we do have other options that will work for you. If the plug you found at the rear of your van look like they would match the photo I have attached, then you can use the Hopkins Custom Fit Vehicle Wiring, part # HM40975. Using this will give you both a 4-way and a...
    view full answer...
    Image 1 for
  • Heavy Duty Hitch for 2021 4500 Chevrolet Express Cutaway
    I recommend the Curt item # C15320 trailer hitch for your 2021 Chevrolet Express 4500. This is a 2 inch class V hitch with a 16000 lbs towing capacity, 2400 lbs tongue weight, and is the heaviest duty hitch for your van. You're going to need a wiring harness to power and control your trailer lights and potentially other functions. I recommend the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector item # 55540. If you're looking to have wiring for both a 4 flat...
    view full answer...
  • What 7-Way and Brake Controller do You Recommend for My 2006 Chevy Express Van?
    To hook up a 7-pin connector on your 2006 Chevy Express Van, you first need to have a 4-way installed on the vehicle. If you need a 4-way harness, that is the Tekonsha T-One Vehicle Harness - 4-Way # 118392. This harness comes with a higher quality converter box than the Curt T-Connector - 4-Way # 55540. Once the 4-way is installed, you are not ready for the 7-way. For that harness, you need the Universal Installation Kit for Trailer Brake Controllers - 7-Way # ETBC7. This harness preps...
    view full answer...

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