Adding brakes to the utility trailer – electrical (Day 1)

Last fall I installed the Tow-Pro into the Ridgeline, now I have to make it so the Tow-Pro can control the trailer brakes.

First off, the brake-less trailer has a four pin plug (Ground, Marker, Left & Right Turns), while a trailer equipped with brakes has a seven pin plug (added Brakes, Reverse lights and Power).

Secondly now that the trailer has brakes I’m adding a breakaway so that if the trailer detaches from the truck, the trailer brakes will bring it to a quick stop. (Honestly as it’s a single axle trailer, I think the A-frame digging into the road will bring it to a stop faster than the brakes will.)

Today’s mission – hang the hardware (junction box, breakaway battery box, breakaway switch) on the trailer.

Step one – Blue Tape. Because, you guessed it – it’s easier to see pencil marks on blue tape than black metal.

Because I want to ensure that the holes are lined up (why does the battery box need SIX screws?) I trace the boxes so I can reposition them if they shift.

Also, the three pieces of hardware are mounted with three different size bolts. I wrote the bolt final hole size on the tape for each component so I don’t end up over sizing the holes.

Drilling holes in metal is easy if you follow the rules.

• Make a divot so the drill stays in place. I use a spring loaded punch.
• Start small – I start with a 1/16” pilot hole.
• Keep it lubed. Sounds counter intuitive I know, but cutting oil will keep your bit sharp. Drilling dry will do more damage to the bit than the thing you’re trying to put a hole in.

Rust is the enemy and it never sleeps. You MUST protect the bare steel from rust.

Step one Galvanizing spray – its zinc oxide. The zinc bonds with the oxygen in the air more readily than the steel will.

Step two – primer. Paint and zinc will form a chemical soap and flake away. Primer creates a barrier between the zinc and the paint.

Step three paint – ignoring the pretty colors, the purpose of paint is to isolate the metal from the oxygen & moisture in the atmosphere.

Now that my holes have protection, it’s time to fill them.

I used stainless steel ( stainless won’t rust.) hardware to mount these devices. If you go with stainless, remember that it isn’t as strong as Grade 5 hardware. I’ve screwed the heads off of stainless in the past.

The bolt ends are out on the battery box so that I don’t cut up my hands or tarp inside the tongue box.

I couldn’t hang the junction box today because there is a wire conduit inside the frame blocking me. I’m going to have to remove the left side wires from this conduit and cut a section of it out. I’m going to reuse it because it’s a perfect way to protect my wiring.