Adding 12 volt

[universalexports]

your on the right track, I would think you would be safe just running in line 12 volt fuses, this would cut out having to go to the fuse box.

[cowcharge]

You can also cut your wiring in half by grounding everything to the trailer frame and just running the hot wires.

[lopo]

Could someone be a little more specifics on this? Like, how do I "ground everything to the trailer frame"? Maybe a photo or two, or at least a visual description of how to do this? I keep thinking I'll get it by osmosis from the forum, but it hasn't happened yet. Let's start with Step 1) "Buy a ___ battery and put it in a battery box on the tongue of your trailer." Then?

[boneneck]

What I did was while all my panelling was off I ran the wires from where I wated light fixtures and outlets (all 12 volt) to a fuse block that I mounted in a "glad-ware container. I mounted the fuse block in the container just to keep things from bumping it etc. Fuse blocks are pretty simple. You just fit a horse-shoe fuse into the slot and hook 1 wire to the posative, and 1 to the negative. From the block I the ran wires to a sealed, deep cycle battery (so I could keep it in the trailer). Sorry the pics so big, but thats the only size I know how to do. If you PM me I'll take some more pics later when I'm home to show you if you like. Right now I'm at work trying to look busy. This is the only pic I have available.

[cowcharge]

I don't have any pics of my grounds. But the trailer frame underneath is just a big steel wire with wheels on it. So if you have a battery at one end and a light fixture at the other, you only need a wire that goes from the + on the battery to the + on the light fixture (the wire that goes into the light switch). To save wire, you then just connect the - on the battery to the tongue of the trailer, attaching it with a ring connector to a bolt through a hole drilled in the frame. Then you do the same thing at the other end with the - wire from the light, attaching it to a bolt through a hole in the frame. The electricity goes down the long + wire to the light, through the bulb, and back to the battery through the metal frame.
If you look at the battery in your car, you will see that the black - wire is attached to a bolt or post in the engine compartment near the battery, instead of just disappearing into the car, using the frame of the car as a big - wire. The drawing is very very simplistic, you should have the + wire go to a set of fuses before it splits off to the lights and stuff, in case you get a short somewhere. That way whichever appliance shorts out only blows its own fuse, and leaves everything else working. It's also a good idea to have a battery cut-off switch, also on the +wire, between the battery and the fuse box, so that with one switch you can cut power to everything in the camper. You can email me if you want more detail than this

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[lopo]

Thanks, Howard. I'm trying to translate this into a list of what I have to buy (battery, fuse box, "glad ware container - ooops, have that - ring connector, whatever that is, and drill bit that will drill a hole in the trailer frame. Oh, and umpteen feet of wire and a cigarette plug type plug.

I think the ceiling 12 volt light fixture might be connected to the circuit that the taillights and other exterior lights are on, but I'm not sure. Hmmm. I don't see being able to connect that to the new battery because I don't have the ceiling panel off and don't intend to take it off.

Oh! And I would like for the battery to power a water pump, I forgot that, and I guess I'll just use a charger I already have rather than connect it all to my tow vehicle battery to keep it charged.

[cowcharge]

Ring connectors are cheap little circle connectors you can get at any hardware store. they're sized for the wire you plan to use, and you crimp them on with those wire stripper pliers. Or regular pliers if you're gentle.
www.google.com/#q=ring+connectors&hl=en&prmd=imvns&source=univ&tbm=shop&tbo=u&sa=X&ei=V3qpT-nwBcnv6AGJ1fiXBA&sqi=2&ved=0CPYBEK0E&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=88ee5c93dfdbc558&biw=1245&bih=716

[cowcharge]

If you already have a 12v light in there, then it's probably already grounded to the frame. Although some of the older campers apparently used the aluminum skin as a ground, in the same way as the frame (dunno what years or models). On mine they used some of the carriage bolts that hold the wood frame to the steel. One was one right behind the right wheel well for the nearby water pump, one under the left rear corner for running lights, one under the left front edge for the converter and the 110v breaker box case ground, and I think one under the kitchen counter for all the lights around the door and the range hood. They were all inside the walls. But you can add one anywhere you want to install an appliance, you just have to make sure that your battery is grounded to the corresponding part of the camper that each appliance is grounded to. If the light's grounded to the frame, you need the battery grounded to the frame. If another appliance is grounded to the skin, then you also need a battery ground to the skin. You can ground your battery all three ways at once if you have different appliances that are grounded different ways, it doesn't hurt anything.

[Deleted]

*raises hand*
Question?

I suppose I haven't looked long and hard enough to find the right thread to answer this. It is sorta related here because I am starting from scratch myself. My 16scs has the 110 v 15-a service still mostly intact, but all signs of the 12-v have been removed. I want to change up to a 35-a service for the 110-v, and add a water system (pump) and a "fantastic fan". My biggest question is how is the 12 volt system tied in so that these appliances will work when it is plugged into shore power? Is that the function of the converter, and is that tied to the breaker panel?

[idqrocks]

Usually the converter will switch power sources when it dectects shore power. I bought an Elixer 25 amp converter/distribution panel.

Here is my setup. Minus the battery. (Probably do that next year). I didn't draw any Ground or Neutral wires to make it simple.

I rocked out MS Paint for like 30 min to make this, so I hope it helps!

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[Deleted]

Thank you for taking the time and putting this up. It answers most of my questions. (So does having the model number, I can read up later on most of it, by looking it up.) The converter still feeds the 12-v when plugged in, feeds from the battery when not plugged. Pretty simple. Does this unit also charge/maintain the battery from shore power, or is a separate charger needed?

[idqrocks]

Yep, it will also charge the battery. I think it has 3 charge modes, but not 100% on that. Got mine off Ebay for around 80 bucks.

Just make sure you don't buy a distribution panel only. (I did, and now its sitting in my closet.

[vikx]

Here are a few parts for your tow wiring and 12 volt system. The battery connects to the self resetting circuit breaker. The trailer hot wire connects to the other stud and from there goes to the fuse block. The charge wire on the 7 way trailer cord also connects to the breaker.

Inside, the fuse block distributes 12 volt power to individual circuits, much as a 110 breaker box does. 3 circuits are sufficient for a smaller camp trailer. One for the upper 12 volt/Fantastic Fan, a 2nd for the pump and maybe a cigar plug and the 3rd for any extras, like a porch light or door side necessities.

A small battery maintainer will keep your battery safely charged and eliminate the need for a converter if your system is fairly simple. Modern RVs require a converter to provide a clean 12 volts to power circuit boards on water heaters, refrigerators and furnaces.

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