Ditto here Ed.
Going over the hill from Redding to Eureka in our old '84 Pace Arrow one year, we smelled smoke. I luckily was near a rare pullout on that winding road, and pulled over. Opening the "hood" I found the chassis battery positive post melting, and about asphyxiated trying to see exactly what was up through the acrid smoke. Somehow I managed to stop the meltdown because things were smoking pretty badly and fire or battery explosion were no doubt imminent. It all happened so quickly, I don't remember what I did; probably reefed off the negative cable to kill the chassis as a ground for the short, wherever it was. Somewhere along the line I added a mechanical cutoff blade switch to a battery post, so if that was on it then and had not melted or welded shut, I would have popped it open. As a relative RV newbie at the time, I think I surprised myself at how fast my feeble brain worked - thank goodness for having grown up on a farm as I was never inherently mechanically inclined, no doubt much to Dad's consternation. A passing CHIP called a tow company (this was before cell phones) and we were towed back to Redding that evening, then towed to a recommended auto electric shop the next morning, a day or two before Labor Day weekend.
The repair guy was kind-natured and seemed up to the task, which entailed patching some wires midway along the chassis frame where they'd shorted out. He worked on it over the holiday weekend to help get us on our way. And we were off again, this time opting to go north up I-5 toward home where I had to be back to work Tuesday. That was Sunday before Labor Day. We get to Roseburg's fairgrounds RV park and I crawl under the coach to see the repair up close, because some vehicle components weren't operating correctly for some reason. Okay, what I saw under there wasn't going to settle my grits. I got lucky and the Roseburg auto parts was open Labor Day, the only open store in town. I bought tons of wire, including about 30 feet of heavy red battery cable and connectors, and did most of the imminently necessary re-repair myself, spending most of the day at it.
Turns out the Fleetwood factory in Riverside, CA, had a reputation for stringing wire. When they came to the end of a spool, they spliced in another of any available color, and kept going. And they stretched wire to make it reach. Several looms of wires, maybe 15 or 20 of varying sizes wire tied together, went from up front to mid-coach where a large hole was cut through the main chassis frame streetside beam along the outside of which they'd been strung up to that point. They went through the hole, across the chassis to the inside of the other main chassis frame beam, along it for a few feet, then the wires split up, some going back to rear lights and such and others up through the floor to the converter under a dinette seat. In order to make everything reach, the installer had pulled the loom tight.
Remember that hole in the chassis frame? They'd actually used a torch on the heavy steel, not a drill, and they not only didn't bother to rubber grommet the hole, they didn't even file or paint its jagged edges, nor was any black plastic loom protectand tubing used for that section. #12 wires pulled tight against such a thing don't survive much road travel, and once one of them had its insulation rubbed off and shorted against the rail, the heat melted adjoining wires' insulation, shorting them as well. The coup de resista'nce was when the insulation on the big fat (#00?) battery cable melted, shorting the 30 foot generator start line. The current running through that really did in the battery post it was fastened to. If a fire hadn't started there, it would have at the short point under the middle of the coach.
The Redding tech had patched a bunch of wires, but little else. So I repaired properly what I could, and strung entire new wires where necessary, obviously including about 30 feet of generator starting cable, everything looser through that hole or bypassing it via a better route, and with the addition of protective tubing(s) around the looms through the hole, and tubing fitted around the circumference of the jagged hole. Surprisingly, the only place Fleetwood had judiciously used that tubing around wire looms was in wheel wells; I guess they thought that was the only place road debris could do any harm. When I got home I took the rig to a Portland auto shop and had them do some more sophisticated repairs and electrical upgrades. State Farm paid for about $1000 of the repairs, including some of the upgrades that should have been done by the factory - the adjustor felt that was just good sense protecting State Farm from future loss. The Redding shop reimbursed me for some of their uninsured bill as well after I complained.
All in all, though I was out an awful lot of personal time, money, effort, and convenience, I think we were pretty lucky. And like Ed, I earned a genuinely high regard for the current (amperage flow) and energy output that 12 volt batteries are capable of. That lead battery post was hot as hades and essentially mush. A few more fuses in the right places might have helped, but many were downstream of this short, and those that were upstream on a panel above the batteries did blow. A master high-amp fuse right off the battery, especially for that heavy genset line, would have been a prudent Fleetwood addition.
Joel
