CURT 56225 Vehicle-Side Custom 4-Pin Trailer Wiring Harness

Easy to install. Perfect transaction

Installed on my 2025 Nissan frontier. Took about 15 minutes to install both the relay harness and the trailer harness combined. All the lights on my trailer work perfectly.

I am 64 years old. In the old days, to install harnesses, one would need to locate, mark, strip/cut, and splice wires to rig a harness. This was amazingly simple. I had a hard time finding the 12 pin plug behind the kick plate. The plug was tucked behind the other plugs and had no flexibility to pull from the wall of the truck. However, it turned out to be very simple. The instructions that come with this package show various steps of progress. However, for a novice such as myself, the instructions were missing information. A quick online search for videos, explained the other steps and within no time, all was connected and mounted. My test light indicates all is working properly. My boat has been in the shop. I am assuming all will work upon connection. Knowing one's way around vehicles is also important. On my Frontier, the kick panel is accessed by prying off the sill at the bottom of the door. Then unscrewing the black plastic retainer holding the kick plate. This retainer is on the upper floor board under the glove box area. One must also understand how to disconnect auto wiring plugs without damaging the clips. Between installing my new hitch and this harness, I would estimate it took this idiot about 2 dedicated hours. A person that has the right knowledge could have installed the hitch and the harness in about 30 minutes.

Works well, made well, and good buy

This works as advertised and installation was super easy. I’m only downgrading to 4 stars because the exposed pin where the trailer hooks up to got loose really fast like it’s about to break off. Not sure if it had some defect but I connect it carefully each time and everything still works as it should.

works good fit my truck nicely easily

It's a good quality harness. On a 2008 Xterra, the harness under the vehicle was very easy. It was also fairly easy to install the harness that goes behind the passenger footwell kickpanel, but when I couldn't find the empty receptacle mentioned in the directions, I noticed a receptacle that was the same size, but had a plug already in it. I switched it out and everything seemed to work but then I realized that the passenger window had stopped working... I went back into the footwell, with a headlamp this time, and found the correct receptacle, which is a few inches further forward, and all issues were resolved. In summary, it is possible to plug this into the wrong connector. Just mentioning to help someone avoid the same silly oversight that I made.

Took 5 mins to install and was done. Used a 4-Way Flat Trailer Adapter Inline Circuit Tester w/ LED to ensure I was getting both turn signals brake and running lights. All work as it should, with the buy.

Works fine Easy to plug in ,

I researched a lot because my trailer marker lights would not work. Turns out Nissan has some weird lighting system that requires you to purchase an add on to make the marker lights work on a trailer. The trailer wiring and hitch was factory installed. It was easy to install and now my lighting system works! Highly recommend this if you have a 2018 Nissan Frontier Pro4X. Priced right too.

Stellar 10 minutes install and perfect fit.

worked good plugged right in and instructions were accurate.

This works perfectly. Park lights work on trailer now. Very easy to install.