Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
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2017 Ram ProMaster 1500
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2017 Ram ProMaster 1500
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Wiring up a trailer usually means finding and tapping into the right wires, but not with this setup. The Curt T-Connector plugs directly inline with your vehicle’s taillight wiring, giving you a working 4-pole flat connector without splicing a single wire. It’s a straightforward plug-and-play design that connects cleanly behind the rear trim panels for a simple, hidden install.
Modern vehicle wiring isn’t built to handle the extra load from trailer lights. This harness uses a powered converter that takes its power straight from the battery through a dedicated hot lead. The taillight circuits only act as signal triggers, while the converter supplies all the current needed for the trailer lights. That keeps your factory wiring isolated and protected if the trailer ever shorts out.
The included black power wire runs to the positive terminal of your vehicle’s battery, giving the converter consistent 12-volt power. That setup ensures your trailer running lights, turn signals, and brake lights work correctly every time you tow. The harness only draws power when a trailer is plugged in, so there’s no drain when you’re not towing.
Once installed, you’ll have a standard 4-way flat connector ready for most small trailers or lighted cargo carriers. It provides running, turn, and brake light functions in one simple plug that matches what most trailers use today.
Because it connects inline with factory plugs and stays tucked behind interior panels, there’s no messy wiring or visible splices. The finished install looks clean and professional, with just the 4-flat plug accessible when you need it for towing.
Customer Satisfaction Score:
95% were satisfied with this product
5% of customers were not satisfied
Ratings & Reviews
I received the product and it fits my car perfectly after installation. It would be even more perfect if the four-needle line was extended by 10 inches. Their after-sales customer service staff are also very happy to help customers solve problems.
Quick easy connections. Would rather the main power wire be all one piece instead of having to splice it on to the box, and there needs to be a option to route the harness outside the vehicle and mount to the receiver. But works for what it is.
The trailer hitch is good but was difficult to install with undercoating making the fit more work than anticipated.
Straight forward install, good quality. Installed on 2018 VW Tiguan.
Another great etrailer.com experience! The hitch fit perfectly. The instructional video was spot on. The wiring kit was an effort to install but that's because of Volkswagen, not etrailer. Couldn't believe how quickly it was delivered! Never disappointing to use etrailer.com!
The Curt wiring harness for my 2019 Tiguan impressed me with its high quality. The connectors were all OEM quality- snapped in with no problem. Once finished installing it tested out perfectly. My only issue was the generic printed instructions included with the harness. Luckily, etrailer has a step by step installation video showing a 2018 tiguan. This made installation a snap. I highly recommend buying from etrailer, quality products and help with installation.
Wire to the 4 pin plug could be a little longer, 4”-6” would get it closer to the receiver.
Made it super easy to install. Watched the online videos on Etrailer which was very helpful, can't beat it. I did run one of wires a bit differently than they did, I went inside the car under the carpet and door sills instead of under the vehicle. Always have good luck with the products I get from etrailer.
Have to agree with the review by Brian, this is not an easy install. Spent hours trying to remove panels without breaking them and then running wires to the connectors. Also spent about two hours removing under body panels to run the power from the battery to the back of the vehicle then reinstalling.
The harness installs easily once all of the stuff is out of the way. Seems to work well, but not sure about sending constant power to the unit all of the time, key on or off. Hope this doesn't have a low voltage use when not in operation, would hate to come back to my vehicle after two weeks in the airport parking lot and have a dead battery.
This installation took me about 2 hours. I already had my '19 Tiguan SE 4Motion up on ramps from installing the hitch receiver. Pulling the trim back and getting inside the rear area to access the tail lights was a very tight fit. Thankfully VW has access panels that can be popped out for accessing the tail light bulbs this that helped. Once I got the drivers side and passengers side connected, which is very easy. I placed the main control box just left of center with the provided double-sided tape. I tie-wrapped everything up nice and neat. The hardest part was deciding on how to run the hot + wire up to the battery. Luckily the Tiguan has an underbody panel you can run the hot wire inside of from front to rear. I also found on the drivers side on the flat surface below the tail light there is a hole with a plastic plug in it. I used that to run the hot wire from the underbody to inside the rear cargo area to complete my install. I did not run the 4 pin connector outside the body, I'll just lay it out flat and close the hatch lid on it, as suggested in the install instructions. If I was going to be towing allot I would have ran the 4 pin outside and under but since this is only for the odd use i did not.
etrailer has turned another one of my cars into a tow vehicle. Just punch in car and they give you all the options and accessories that go along with it. 2019 Tiguan hitch and wiring was straight forward with a video and the best price. Thanks again
Matt
Plug and play made it easy. Being a volkswagon made getting to it harder than most cars.
Install is do able, just takes awhile. Never even looked at the instructions. Just follow the videos. I have a 2021 Tiguan. The part of the harness with the plug needs to be longer. By the time you get the plug through the hole to get out of the hatch area. There is very little wire left to get back to the hitch. Had some issues with initial order. My order was over $99 so free shipping. Unfortunately the bracket was out of stock. Even though it said it was available. Did receive email telling me delivery would not be for 2 months. Offering me the opportunity to order a different bracket. Twice the price. Email never mentioned the harness that was in stock would not ship until the bracket came in. Lucky I called and learned about the shipping issues . Was able to cancel and reorder with a bracket that was in stock. Only slightly more expensive.
Very well-made kit and helpful installation video.
The installation video was very clear about drilling a hole in the trunk to pass through the hot wire routed under the car but made absolutely no mention of how to route the 4-pole plug from inside the trunk to the receiver outside the car. The opening needed is 1-1/2 inches X 3/4 inches which required drilling several holes and then filing the slot.
For what it is to expensive
A quality product that plugs into the vehicle wiring - no splicing needed. The only drawback is that the installation instructions do not adequately explain how to remove the interior panels in order to access the tail light assemblies. The instructions mention removal of one clip on each panel; there is a lot more to it than that! The average DIYer may not be able to remove the panels without better explanation. Better documentation and/or video would be a big help.
Jon J.
1/16/2021
I installed the trailer light kit on my 2019 Tiguan about a year ago. It works fine for the lights on my utility trailer. Rather than running the 12V power wire all the way to the front of the car, I installed a cigarette-lighter end of it and plug it into the 12V accessory plug in the cargo compartment. Works great.
Installation is easy, but time consuming. The two grommets holding the trim covering the tail lights were destroyed during my installation, even though I used a grommet tool to try and remove them. Not really an issue as I keep an assortment of them in my garage. I also found there is a vent covering the taillight harness, so all you need is to pull it out to access the wiring. I did take the screw under the 3rd row seat release out to help get the trim out enough to run the wires through. I ran the wire to the battery up the left side, under the trim along the doors. Once in the front there is a grommet up behind the brake pedal that goes right to the engine bay behind the battery. I put a small cut in it and ran the wire through it as it is soft rubber and pretty well seals itself around the wire.
David M.
3/17/2020
Have not had any issues with the harness. Works perfectly.
Very easy to install and instructional vidio is great if needed. All hardware worked perfect
Worked exactly as it should and super simple to install. Other companies didn’t work on my 2023 Volkswagen Tiguan SEL R-Line but this one works perfect.
Hitch install was easy. Wiring was straight forward for the most part- routing the power cable from the trunk to the battery took a little creativity/ effort without a lift.
Installed easily enough. Tapped power from an existing trailer control box.
Hitch was nicely protected, the curt wiring was already opened and seemed to be a returned items with rubber bands. Paid for a new one seems like it should have been an opened box price...almost $[XX]
Installation video is excellent. Toughest part is routing the power wire to the battery. Trailer connection wires should be 8” to 10” longer for proper location nearer the receiver.
Fit's 2022 Tiguan SEL perfectly. Purchased an adapter plug for the rear USB power outlet so no need to run power wire to the front (battery).
Getting my vehicle ready to tow was a bit more difficult than advertised. Some details not as clear through the website as they could be, which caused a hiccup and delay in accomplishing the feat. Lauren A was the hero in helping me order the right harness, and get back on track! Once the hitch and correct wiring harness were installed, my vehicle was good to go! Thank you so much!
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Yaakov M.
6/2/2022
1-Year Follow Up - I have only used the hitch for one haul so far but everything works well.