I have a 1978 26ft Class A Georgie Boy Swinger Executive Lounge Motorhome on a Dodge 440 with appx 72,000 miles and the coach runs exceptionally well, looks flawless and very well kept. Just recently a mechanic was installing a new engine battery and inadvertently installed it backward, just long enough for there to be a buzzing sound before realizing what he had done. In that process there were a few things that got 'buzzed' but have since been rectified. There are two fusable links under the coach under the drivers area but underneath attached to what looks like the chassis rail. In this area are what looks like a million wires coming and going but these two fusable links are quite obvious and easily reachable. I am not in the slightest mechanically inclined so if I get something wrong or don't know what to call it forgive me, I'll try. These two fusable links are of strong wire with a fuse in the middle of each link. The one link, apparently had been attached to what makes the coach start or get juice to start. That was fried, it has since replaced and works like new. The other fusable link hasn't yet been replaced as at the time didn't think it needed to and now my auto step and front running lights are inop. In the beginning or right after the battery was installed incorrectly they worked fine, or at least seemed too, now they don't at all and these two items alone are what are causing me to miss out on these awesome days of weather here in Denver with using my coach. The auto step comes out too far and it's old school step so it's made out of steel and if I hit something with it, it'd be a mess. My question is, should I be looking at the remaining fuseable link first? It seems that the running lights and auto step should also be connected to whatever starts the coach or the area in which the other fusable link is located right? Any help would be greatly appreciated. Thanks!
Those old Dodge chassis' relied on fuseable links for just about everything. Be sure to rewire ALL of those links with the proper fuse link wire. The fuse link itself is a sacrificial wire which burns if a short circuit occurs. It is possible when one burned, it damaged another one close to it. Also, I have seen many burn internally without damaging the insulation. So give each link a pull. If it is burnt inside, the wire insulation will stretch like a rubber band, so don't rely on visual inspection only. Lastly, have the charging system checked out by a shop (or yourself) to make sure the alternator is still charging. Reverse polarity will take out the rectifier diodes in the alternator in many cases.
Thanks for your reply. I will just go ahead and replace that entire fusable link then since it's the only one remaining unchanged. As for the charging system, I think I may have been blessed in that area. The alt is still charging as it should. The alt gage works as it should and registers as it should. The battery is also holding a charge.
I do boat work and see this sort of thing a lot, but usually because it is dark and/or the weather is bad.
Yes - you will have to search out all the fusible links and there are probably a few. But, there is also a high (read near certainty) that the alternator was damaged and charging isolator was blown out.
The isolator is a finned aluminum thing with at least three big terminals. It is usually in the engine spaces in an RV. A heavy wire from the alternator will go directly to it. It has to be disconnected to be checked.
Any decent autoparts store can check out the alternator. If it is bad and there is no replacement handy, walk it over to an automotive electrics rebuilder and tell him what happened. He can replace the diodes and check out the rest pretty fast. (Maybe not cheap.)
Matt & Mary Colie
A sailor, his bride and their black dog going to see some dry places that have Geocaches in a coach made the year we married.