Ok, so I have most of the wiring sorted.
I found a "Honda civic" Napa battery that fits nicely in the front battery box.
Here is the problem. I have a green wire (ground), and two orange wires.
Both are heavy gauge and one of the orange wires services all of the 12v
needs inside the Airstream.
I have a second orange wire that I have no idea what it does. (I have a guess). When I opened the inspection holes behind the gaucho, the street side has the termination of this orange wire. It is in a pair with a green (ground) wire. The orange wire ends and marries up with a wire that disappears down the street side chassis member, it has a jacketed wire with two wires inside of it, one red, one gray. I believe this may be for the trailer brakes.
Can someone please confirm that this is what these wires are for? I can get the test light out and see what I get, but I am sure that someone on this forum has had that inspection box open and knows what that second orange wire is for.
Any help much appreciated and I can provide pics of what I am talking about when I get home after work tomorrow.