HOW TO: Junction Box for the 7 Wire Trailer Harness, under the front dinette seat

[John E Davies]

Here is a related thread, I installed a similar box up front under the jack: ... https://olivertraveltrailers.com/forums/topic/2688-how-to-junction-box-for-trailer-harness-repair-or-extend-the-harness/

This all came about because I wanted to install a ...  Redarc DC to DC Battery Charger .... and I needed to know FOR SURE that the wires were big enough. 12 AWG is the absolute minimum according to Redarc, and bigger is always better, especially in an Ollie with a very long run back to the batteries. Here are the existing butt splices, half of them are absolutely buried under the sewer pipes. Time for a J-Box!

So I cut all the splices, and dragged the ends up to where I could inspect the wires. Most were OK, but the white Ground wire was not. Somebody extended the front wire with a smaller sized one. Darn it!

I bolted down the box next to the 120 VAC outlet. I spliced into the green and white running light wires and brought them up to the box via the bottom hole. The other wires come in from the left and right sides. I ran heavier 10 AWG black and white wires (power and ground) from the box back to the appropriate posts. So now the Redarc charger will not suffer from excessive voltage drop, and with the easy access, it will be very simple to troubleshoot any future 7 Wire Harness problems.

The new splices are easy to ID because they have clear spiral wrap plastic, and they are secured to the inside wall using a 1" thick block of HDPE plastic, bonded with JB Weld directly over the small LED light.

 

The placard goes inside the J Box using 3M double stick tape.

Here is the placard, in  Apple Pages format:

Oliver Junction Box wiring placard Rear 7 pin.pages

Note that I indicated where those marker light splices are - I hate not knowing!

John Davies

Spokane WA

 

 

 

Edited March 12, 2021 by John E Davies

[Geronimo John]

Yep, found it now!  🙂

[MAX Burner]

Very clean - nicely done!