Forum Discussion

skripo's avatar
skripo
Explorer
May 12, 2015

Electrical connection box help needed for weekend trip

When I purchased my trailer the manufacturer had put a household junction box near the battery.

2 wires went to the battery and all the other wires where connected together with twist on wire connectors. The dealer added a fuse on the battery power line, dropping 2 steps of wire thickness to do it.

I myself added something and now it is now a big corroded mess. I've lost power and want to redo the whole thing properly.

I am looking for a buss bar or connection box to bring it all together but found nothing other than a DIY solution consisting of a water proof junction box and 2 bus bars. I don't like this solution.

Is there a nice junction box specifically made for connecting a DC battery to several thick wires? Maybe even a battery fuse?

I looked at Home Depot, after market car stereo, and solar equipment providers.

All help appreciated, I am leaving in 2 days.
  • Blue Sea or MidNite would be my choice. Norther AZ Wind and Sun has good prices on
    MidNite breaker boxes and breakers. These are rated for DC applications.
  • I like the distribution block idea. Due to time contraints I bought an exterior waterproof junction box and 2 bus terminal. I modified both to work together but am not sure how it will turn out.
  • Power distribution block available at most big box hardware stores and Ace hardware.
    Come in various configurations. Two pole versions of these are good Power distribution blocks.
    They need to be protected from weather like most.
    Use an ample amount of electrical corrosion grease on all conductors.
    It was common for manufacturers to install 4 inch octagon or four square boxes under the tongue of rigs. There are rated for that kind of area as they are only NEMA 1. But they did it anyway!
  • skripo wrote:
    When I purchased my trailer the manufacturer had put a household junction box near the battery.

    2 wires went to the battery and all the other wires where connected together with twist on wire connectors. The dealer added a fuse on the battery power line, dropping 2 steps of wire thickness to do it.

    I myself added something and now it is now a big corroded mess. I've lost power and want to redo the whole thing properly.

    I am looking for a buss bar or connection box to bring it all together but found nothing other than a DIY solution consisting of a water proof junction box and 2 bus bars. I don't like this solution.

    Is there a nice junction box specifically made for connecting a DC battery to several thick wires? Maybe even a battery fuse?

    I looked at Home Depot, after market car stereo, and solar equipment providers.

    All help appreciated, I am leaving in 2 days.


    my RV is the same way, I imagine all of them which have a battery on the tongue are.

    those wires are:

    1. heavy wire that leads to a DC fuse block inside the RV
    2. heavy wire that leads to your 7-way connector for "charging"
    3. heavy wire that runs to the battery / fuse
    4. lighter wire that runs to your emergency brake switch
    5. whatever you added

    If you want to clean that mess up, two options. First, undo the twisted together wires, scrape 'em with some pliers, twist 'em together again and use an outdoor burial grade wire nut. The burial grade means it's more protected against moisture, and contains a dielectric grease that prevents the wires from corroding. once you have the nut on there, wrap it with electrical tape to keep the nut from going anywhere. don't worry about the short reduction in wire gauge for the fuse holder. wire resistance is a function of gauge and length, such a short length doesn't much matter.

    second option, undo the twisted wires and get rid of the box. scrape the wire ends with pliers and crimp on 5/16th ring terminals - get the good ones from West Marine or Fastenal, not the junk ones from Ace / Home Depot. Next up get nice Bussman marine breaker, 30 amps (or whatever based on the smallest gauge wire connected). One side goes to your battery, put all the other rings on the other side of the breaker. Mount the breaker someplace handy as allowed by your wiring and put some dielectric grease or battery-terminal spray on the terminals.

  • RoyB's avatar
    RoyB
    Explorer II
    We use LOWES for all thing electrical and also order alot of 12VDC ITEMS from BLUE SEA. Once you have the part number of the fuse assy, terminal strips, etc you can order them from AMAZON using the BLUE SEA PART NUMBER... BLUE SEA also has a 12VDC SUB PANEL that is nice to add for more 12VDC FUSED circuits

    Every thing I do with my trailer is cables that have ring terminals. Makes for neat installations...

    I like to make all my mods neat and to some standard along with drawings etc...

    NO RATS NEST wiring using WIRE NUTS for me...

    Roy Ken
  • QUOTE:

    When I purchased my trailer the manufacturer had put a household junction box near the battery.

    Household junction box? can't be.

    I myself added something and now it is now a big corroded mess.

    What did you add ?
  • This will not help you in your 2-3 day time frame (well, maybe with Prime)... but look up Blue Sea Systems. They make items to what you are referring to and those items are generally made for boats. Boat electrical systems are very similar to what is found on RVs.

    I actually installed a 6 fuse version of this for accessories on my ATV and it works as I would expect.

    Blue Sea Systems ST Blade Fuse Block - 12 Circuits with Negative Bus & Cover

    It does not have a household style bus bar for +, you would need to also install connectors. Good news is, you could independently use different fuses. Or maybe Blue Sea Systems makes something exactly as you are looking for but was not part of my search criteria.