1979 28m. Where to start

[oneshort]

My wife and I have our first Avion (1979 28' model M) and it looks like it will be keeping me busy for a while. I'm sure I'll be able to take care of all it needs eventually myself, but I've run into two perplexers already.
- I'm struggling to find an adapter to allow me to install standard 14" ceiling stuff in this Camper's ~18" openings, specifically a fantastic fan and normal opening vent (both of mine just have a translucent cap glued & screwed over where the vents used to be). I'll make a square out of 1x1-1/2" or so aluminum angle with the corners welded if I need to.
- Someone had hooked up a battery backwards and melted the insulation off of the large (6g?) 12V wires that run between the batteries and the charger panel. I'm struggling with finding a simple way to route the new wires without ripping too much apart. Best guess is inside (under BR sink) into the refrigerator area, then south and run forward through the tiny lower hatch compartments. Then what though- still a few feet short of the front. Perhaps down & out, then conduit outside of the belly tin up to the battery box. Is there a better, not-too-destructive way to follow the wiring's original path?

I'm still poking around- it's amazing how much info there is here.

[leighlandon]

Welcome!

Here a thread that may help you with the 18".

https://www.aviontrailers.net/viewtopic.php?f=9&t=1223

[KYAvion]

Welcome to the forum! That’s too bad about your converter wires. The other option would be to drop the belly pan, unless your able to pull the new wires through via the old ones? I imagine that’s unlikely though.

[oneshort]

I'm going to try to avoid dropping the pan if possible. I'm sure there's little chance of using the old to pull through a replacement- Judging by how toasted the exposed wiring is, I'm sure within the walls it has become one with the trailer insulation and whatever else it touched. The exposed wire near the battery box is much worse. .
I enjoy projects. I'm hoping if I learn anything useful I might be able to help someone else.

[KYAvion]

How does the copper wire itself look for the one you have circled? The lack of insulation in that spot isn’t really an issue since it ultimately bonds to the trailer frame anyway.

What about where the 12v neutral bar attaches to the skin? It looks black. Is that scorched?

[Salty]

Am I the only one to notice red wires in the ground bus? Seems a bit unusual to me.

[KYAvion]

I saw that too and thought it was odd that Avion (or someone) chose that color. Maybe they justified using red since there’s a white stripe. Still odd though.

[oneshort]

I hadn't noticed all the reds on the ground bus. I ran out and checked and I can breath again, it's legit. PIcture stranded 14/2 red romex with standard black and white conductors. They just didn't peel the red sheathing off.
Yes, I'd say that bracket is scorched. I bet that bracket used to be varnished or painted? The bracket mounting screw appears to just be in the paneling but the bar is bonded at the other end so I suspect it got a bit warm passing that much current.
The white ground wire has just a shred or two of plastic left on it at the battery end. I'm sure it still passes electricity, but doesn't look too pretty. I've run new 6g from the converter to the battery (both black and white), Just waiting for a couple parts to connect it up. The hot that used to be for the power tongue jack is a dead-short somewhere along the way after leaving the fuse panel. I'll pull another line for that as well in case I swap out the hand-crank jack it's got now.
I've also replaced the leaking propane regulator/selector, and the refrigerator. I'm watching for a sale on A/C units, but am considering a mini-split (quieter, more efficient?). The split copper water lines will get replaced with pex since I've already got the crimper and rings. I'll have to replace the cracked sewage valves (and hope the tanks are empty). That's something that will be completely new to me.
On the bright side, the Furnace works

[KYAvion]

You could always run a wire from the battery to the tongue jack with an in-line fuse.

What are those two flexible copper lines at the bottom in your pic? Propane? Water?

[oneshort]

The two copper lines are hot/cold water supply to the bathroom sink/shower (to the right of the picture).
I've finished running two 6awg wires from the battery box to the panel, as well as a 12g for a potential electric jack. All go through the vanity base, under teh shower bench, through the Refrigerator access area, along the outside storage, up under teh front couch and then down into the 7-way connector cable's access area and out. I also fixed a short keeping the rear 12v lights from working- There had apparently been an electric ventilation fan in the front ceiling at some point. The bare wires were stuffed into available holes in the aluminum to hide them. Three 10A fuses later I found the issue. The electric's coming along. I'm not sure yet if it was a good idea but I put a resettable 50A breaker inline at the positive battery post to replace the inline cracked fuse holder. I'm slightly concerned since it's polarized (ie., silver & gold posts are marked Bat & Aux). That means half the time it will be backwards (charge vs draw). Also, I had to drill a hole in its mount since as (poorly) designed it would have kept the plunger from popping out or being able to be reset.
Most of the lamp bulbs have been replace by LEDs purchased through Amazon (LeMeng 12V BA15S LED Bulb S8 SC 3W 300Lm 2700K Warm White,DC Bayonet Single Contact Base). The color matches the incandescents very closely according to my aging eyes.

The next thing that has my attention are the non-functional window cranks. I wish Avion had bolted them in rather than using rivets.