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Running trailer wiring can be a pain when you have to dig into factory wires. This Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector skips that step. It plugs straight into the factory connection point behind the driver-side trim panel so you don’t have to cut or splice a single wire. Once connected, the harness gives you a clean, tucked-away setup that looks factory-installed.
The 4-pole flat connector supplies the basic lighting functions—running lights, turn signals, and brake lights—needed for safe towing. It’s the common standard used on most small trailers, so once installed you can hook up and go without special adapters or rewiring.
If later on you need to run a brake controller or charge a trailer battery, the 4-way plug from this harness is the starting point. Add a brake controller install kit and 7-way adapter (like part # ETBC7) to convert it to a full 7-pole system without replacing anything you’ve already done.
Finding where to connect can be confusing, but this harness is designed for simple access points. The plug locations are behind the driver-side rear trim or under the cargo floor, so you can reach them without running wires through the whole vehicle. Once found, just separate the factory halves and insert the T-connector in between—it’s that straightforward.
Customer Satisfaction Score:
92% were satisfied with this product
8% of customers were not satisfied
Ratings & Reviews
Got it, put on, and now using it.
Thank you very much. I will give you guys a call if I need any thing trailer related from now on
I received this product in a timely manner, it was in perfect condition and installed very quickly as the product claims. This company has won my business.
This was a very straightforward installation, even better that some I had purchased for previous vehicles. Just Plug in, some light trim panel r&r, a little cable tie work.
Good product and value priced. Good installation instructions.
eTrailer has been my go to place for many years. Again, this order did not disappoint.
We can now haul the Harleys with the new car!
installation video was really informative. I was able to put in my product with great ease in no time. Product was delivered fast.
etrailer is always my first choice for trailer and related products. Their install videos are most helpful and one main reasons I go there first! They have the best prices I have found. Fastest shipper I have ever dealt with. Great personal service too! Thanks
Wiring harness fit well, instructions were excellent. Installed with out any surprizes.
I installed this on a 2008 Chevrolet Uplander. Instructions were clear. Installation was easy and it worked as advertised.
Harnness was easy to plug in ran wire behind tail light than down to the hitch buddys car he ordered the hitch u whole job took about 40 minutes too do great products wont order from anyone else thanks
Another slam dunk from etrailer
Jim R.
6/16/2021
Good
Excellent quality and service. Shipping was quick. Installation after watching the vids was beginner level easy... highly recomend this company.
This makes trailer wiring a total Breeze!
I remember the old days of trying to hardwire things in. You paid about the same money and it took forever. This works with simply plugging it in. How can you go wrong!
The hitch got delivered before the shipping notice arrived!! Perfect fit and finish (as usual) Had to change wrenches a lot as both metric and inch sizes in use. With cleaning rust and restoring threaded holes and painting around, reality install time (working alone) about 3 hrs, incl. wiring.
Installed it in 15 minutes.
Easy to install. Only complaint the harness could have been just a little bit longer. Otherwise great product.
Bruce L.
5/4/2016
Great product easy to install
quick and painless install. Loosened LH rear side panel on my 07 uplander, located the unused connector in the harness just in front of the taillight and behind the rear a/c unit. Plugged in. Tested works great.
Don't have a picture, but installation of the harness in my 2007 Chevy Uplander was a 'piece of cake' - my van was set up for the 'T-connection'. And, it worked without a hitch on a [rental] trailer.
Wiring harness fit my 2008 Chevy Uplander as advertised. I just had to open the interior wall of the vehicle, plug in the harness into an existing receptacle and I have trailer lights. Great product at a very reasonable price
Great product, priced fair. I found it very easy and quick to install in my vehicle and it works great. I use it for connecting my trailer light to my tow vehicle, and have found no problems at all. I would tell my friends that need to do wireing to look you up.
The hardware was fine,, I have not yet instaled the wiring harness
Fran
5/31/2017
Just installed it, had an open plug ready to go was working in 10 minuites. Checked ut fine.
Wiring harness worked perfectly for my 2005 Buick Terazza. I was able to find the connector to use by pulling back the drivers side plastic panel (didn't have to remove the entire panel). My connector was located just behind the compressor for the rear air unit. The connection was straight forward. The hardest part was trying to determine how to route the harness through the vehicle to the hitch area. I ended up running the cable through the tail light grommet on the drivers side and down between the bumper and frame.
Well worth the $$ not to have to splice and figure out which wire does what.
As always, e trailer came through with a simple solution for a sometimes difficult problem. Great quality, reasonable price and great customer service. I have purchased several items in the past and will continue to be a loyal customer. The harness is simple to install and all components are top quality.
Knut
6/3/2016
It functions perfectly, just as the day I installed it. I am and will remain a loyal customer.
The wiring harness I purchased fit exactly as advertised, went in easily and worked great! The only problem I had was that the vehicle did not have a hole to run the wiring to the outside. This was quickly solved with a hole saw.
Ed
9/14/2016
Still working as good as the first day it was installed.
I've purchased this harness one year ago. The instructions were clear, and it was very easy to install. All you need to do is to pull off a rubber seal of the rear lift gate, unscrew one (or two, don't remember now) screw(s) on the rear left trim panel, and slightly open up that panel. The vehicle's harness is right there, so you'd just plug this one into it, and then run it under the plastic threshold to the center of the van. All the trailer's lights (running lights, break lights and turn signals) work nicely now.. It also can be easily hid from the view under the rear plastic threshold when not towing, and pulled out when towing. The wires and insulation feel solid yet flexible. Happy with the product.
Leo B.
6/3/2018
After a year, no issues with the harness.
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Greg H.
6/24/2015
still working like a champ. Thank you