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Adding trailer wiring doesn’t have to mean tapping into factory wires. The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector plugs right into existing connectors behind the rear trim. It’s a straightforward setup with no splicing, cutting, or wire tracing required—just plug it in and you’re ready for towing lights.
Factory wiring is delicate and costly to replace, so this harness includes a circuit-protected powered converter built with surface mount technology. It uses only about 5 milliamps from the tail light circuits to trigger the converter, which then draws power directly from the battery to run trailer lights. That setup keeps the vehicle’s internal wiring isolated and safe from shorts or overloads on the trailer side.
The included 4-flat connector provides the basic lighting functions needed for safe towing—running lights, turn signals, and brake lights. It’s the standard plug used on most small and mid-size trailers, so once it’s installed, you can easily hook up and go.
If you need more capability later—like trailer brakes or a 12V charge line—the 4-way from this harness can connect to a 4-to-7 adapter such as part #37185 or a full brake controller kit like #ETBC7. That means you can start simple and expand your towing setup without having to replace your existing wiring.
Customer Satisfaction Score:
96% were satisfied with this product
4% of customers were not satisfied
Ratings & Reviews
Easy to install in my 2011 Acura MDX. Less than 10 minutes. Works great. I ran the wiring through the bumper instead of out through the tailgate. I also bought a mounting bracket and attached it under the car so the wires wouldn't flap around.
First of all, after placing order and got received was about a week! That is awesome, usually prep for shipping takes a week from others stores! Second but not less meaningful, quality of unit, beyond expectations, wires are solid, crimping nice and even.
Installation process is simple as it could! But, I my self a tech and put in the installation a little changed, instead making a hole for a ground I used factory ground point, and location of box I moved in a left front part of storage compartment, that will reduce stress for a wiring and give me more room to store rest of wiring. After it I did check connector for output voltage all good and steady. Haven’t have time to try it with a trailer but 100% sure all will be good!
Thank you
Called for information on multiple brands of trailer hitches. Judy was my rep and did a wonderful job of answering my questions and ensuring I had the best pricing available. Really quick delivery, infact I was surprised how quick. I'm a fussy shopper and etrailer.com hit this one out of the park. I'm highly satisfied with my hitch, end electronics.
Part and installation exactly as described. Took me 2 hours - start to finish.
Being in AZ I didn't have any rust etc. to contend with nor any threading issues. I did use WD40 on the rubber pieces and in the holes for the bolts.
My driveway is at a slight down slope - so I backed into the garage (chocking the front tires) and further elevated the rear-end with the use of a 2x6 and 2x4s. This allowed me to have several additional inches of space. Also - for the spare tire - use the spare tire crow-bar to lower the spare tire (pop the little plastic piece on the floor of the rear end, insert the crow bar, then rotate counter clockwise - the tire will then lower).
I did not have a 2nd set of hands so I used a bungee cord to hold up the hitch on the passenger side while I drilled the first bolt on the driver side.
It helped greatly to have a drill with a socket adapter (3/8" and 1/2") and extension for each. Picked up the adapters before installing after reading the reviews of tight quarters and painstakingly manually tightening the bolts. Adapters are $4/each at local hardware store and totally worth it vs using a manual socket.
A torque wrench is highly recommended since I used the power drill to screw in the bolt - then I used the torque wrench and surprisingly it required a bit more turning to get to the 136lbs of torque required as called out in the instructions.
I took a pick of all the tools that I used to install.
Installation was a breeze once the spare tire was lowered and the muffler mounts were removed. Having an extra set of hands definitely makes lifting the hitch a lot easier but I've also been able to use a floor jack as well. I also installed the C56038 which only took a few steps and it remains out of the way when not in use. All in all it's a solid hitch and it tucks nicely under the bumper.
Buying from retailer was a snap. I researched this purchase for a while. etrailer had the best prices and was loaded with information. Hitch and wiring arrived quickly and as described. Having watched the videos on their website installation was a breeze. I would not hesitate to order from here again.
I've not yet installed the item. It appears to be and function as stated. It is priced right and was delivered in a normal time frame. I am awaiting resolution with Acura of a issue that developed with the original connector a third party supplied the dealer with before I change out and lkinstall the new connector
Wow. Super fast shipping, and a great product, as usual. You are my go-to source for hitches and wiring.
Mikecrowley
1/2/2019
Both products are awesome. Perfect fit harness and even better hitch that is very heavily built. Love them.
As always with etrailer, product alternatives were broad, selection and ordering a snap. Product arrived on schedule as promised, though UPS did manage to insert a few extra holes in the box. No damage to product beyond scratches in powder coat.
Installation this weekend.
John O.
5/17/2018
The install still looks and works great.
Product (trailer wiring) was delivered yesterday and installed after dinner the same evening. The install video on your website was a tremendous help, and I surly appreciate the knowhow of your installers. Took my time, was careful and it went smooth - anxious to test this coming weekend but I don't foresee any issues.
John H.
5/21/2020
Still working great after a year of infrequent use but good to have.
Everything worked well. The wiring harness was easily installed as was the hitch receiver. Both have served me well the past year. Thanks etrailer.
Mike
10/29/2018
George, the wiring worker well. Everything fit as promised. Thanks
I bought a trailer hitch and wiring harness and everything worked out exactly like the sales person said for a great price.
Tow H.
7/8/2016
All good thanks for the follow up!!
I installed the wiring harness, but to my disappointment it didn't work. When I was gathering up the parts and tools, I noticed that there was a red fuse in the plastic bag of accessories. I checked the controller and found there was a fuse holder on the power line. When I opened it up, lo and behold, no fuse. Installing the fuse fixed the problem and the lights then worked perfectly. If you look at the picture of the harness, you will not see the fuse holder, and the installation instructions never mention it. I'm sure the fuse was a product improvement, but the installation instructions should be updated to mention it.
Sam N.
3/16/2015
I had the same problem. I had to watch the video on the website. The instructions included with the harness provide almost no help. Once I put in the fuse, the harness works fine. Also, the harness does not come with the pictured dust cover. Etrailer customer service is great and sent me a dust cover at no charge.
I've always gotten quality products from etrailer and the Curt line maintains that tradition. The receiver and wiring harness for my MDX are top quality, were really easy to install after watching the videos and saved me hundreds of dollars over the Acura branded parts.
Jim H.
1/18/2016
After a year Im still very pleased with my receiver and wiring. I use the receiver at least weekly for a Thule bike rack, but the wiring harness only rarely.
I have ordered several thing from eTrailer over the last few years and have been very satisfied. Everything I buy seems to ship immediately (usually same day) and arrives as ordered a few days later. Their installation instructions and videos are always spot on and have been very helpful. I haven't yet installed the wiring kit I just received but have no doubt it will work well and the instructions will be spot on.
Marshall
7/5/2016
Installation was simple. Only took a few minutes and with the video instructions you can go wrong.
Etrailer rocks like a young Mick Jagger.
I received my Acura MDX trailer hitch and wiring in less than 24 hours...despite the fact that it was supposed to be about 6 days ground.
online videos and great construction made installation a snap.
I will buy from Etrailer time and again
Jtw
12/18/2014
Weve put many miles on our Acura MDX trailer tow package from ETrailer and the whole rig right down to the wiring has performed flawlessly.
Installation was straightforward as the videos indicated. Trailer hitch looks and works great. I am very happy with this purchase.
Easy to installed highly recommended for novice installer and dont forget to put the fuse in also
Easy Install. Use the factory grommets in the floor and rear body to run the wiring to make it look like factory. Use the videos on their [online] page for guidance.
Very easy install. Quality product.
Exactly what I was expecting for my Acura. Just a breeze to put in and worked perfectly. I can’t believe it ‘could have’ cost me $[XX] to plug in a wire?? THANKS!
Brooke M.
11/26/2024
Thats awesome, Steve! So glad to hear this harness worked out for you. There is nothing like a project thats completed smoothly!
Steve
11/27/2025
FSNTASTIC!!!
Very happy with the quality and straight forward installation. Hitch and lighting work great.
I made a mistake on my previous review. I wasn't paying attention. The installation on this was a breeze. Decent instructions, although they were hardly needed.
Very easy install—no need to buy a more expensive harness. I ran it through the jack compartment to the panel on the left rear where it simply plugs in and I attached the ground to the lower existing bolt with the existing nut. Simple as that. The cover for the panel where it plugs in pulls off from the top with the help of a flat screwdriver. The instructions are very thorough.
Excellent and easy to install. Great Customer Service.
Lazer S.
9/30/2025
Install looks great, Tracy! What are you going to be towing?
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Mike
10/29/2018
Although Ive not had a opportunity to use the harness, it meter check out.