Factory Brake Controller
5 Year Member
Joined: Jul 2019
Posts: 186
Likes: 61
From: KY
I had a similar issue a couple years back when we had bought a new Sonic camper. I bought it in Ohio and towed it back to KY. I had a Prodigy 3 controller in my Nissan Xterra, and had to crank the gain WAY up to make the brakes halfway work. Then, when we were almost home, the controller suddenly said "No Trailer". I pulled off thinking the trailer plug had fallen out. Nope, still there.
Since I was only about 20 miles from home, I just pulled it the rest of the way with no brakes. Once I dug into it, I found the factory had used WIRE NUTS to make the connections from the trailer pigtail to the wires going back to the trailer brakes! Since they also did not secure the pigtail very well, it flexed enough to pull the wires apart. No junction box either, just spliced under the front of the trailer. That wasn't the best part though! They used 14ga wire from the pigtail (which was 10ga) all the way to the brakes themselves! No wonder I had to crank the gain so high...The brake magnets were not getting full voltage.
I ripped out every inch of that tiny wire, installed a water proof junction box with a terminal strip, ran separate 10ga wires from the J-box to each brake, then spliced them together on the terminal strip. During the test trip to check the brakes, I had to turn the controller gain back to normal for that size trailer since the brakes were now getting full voltage due to the 10ga wire.
Since I was only about 20 miles from home, I just pulled it the rest of the way with no brakes. Once I dug into it, I found the factory had used WIRE NUTS to make the connections from the trailer pigtail to the wires going back to the trailer brakes! Since they also did not secure the pigtail very well, it flexed enough to pull the wires apart. No junction box either, just spliced under the front of the trailer. That wasn't the best part though! They used 14ga wire from the pigtail (which was 10ga) all the way to the brakes themselves! No wonder I had to crank the gain so high...The brake magnets were not getting full voltage.
I ripped out every inch of that tiny wire, installed a water proof junction box with a terminal strip, ran separate 10ga wires from the J-box to each brake, then spliced them together on the terminal strip. During the test trip to check the brakes, I had to turn the controller gain back to normal for that size trailer since the brakes were now getting full voltage due to the 10ga wire.
5 Year Member
Joined: Aug 2018
Posts: 9,099
Likes: 3,211
From: Kentucky
I've used wire nuts, they actually work really well when done right. Fill with dielectric grease, fold over and tape against the wire run, a layer of rubber tape to seal.
I otherwise will solder or use breakout boxes in exposed areas, and push connectors in non-exposed areas.
On my long-term trailers, I run liquid tight tubing from the front breakout to a LT junction box, then more LT tubing to the corners. It's super overkill, but I never have to deal with wiring or connector issues on those trailers, just degraded 7-way plugs and dead batteries.
I otherwise will solder or use breakout boxes in exposed areas, and push connectors in non-exposed areas.
On my long-term trailers, I run liquid tight tubing from the front breakout to a LT junction box, then more LT tubing to the corners. It's super overkill, but I never have to deal with wiring or connector issues on those trailers, just degraded 7-way plugs and dead batteries.