OK, got the alternator fixed and we are back in business. Gerald is correct in that you can easily drive the coach (C12) without an alternator. Just take the belt off, use the generator and the house air.
Now I have a confession, hard as it is to admit. My first of three alternator failures happened when I jumped the toad off the chassis batteries with the coach engine running and let the cables slap together. No, wait, that is not the confession, could have happened to anybody that rainy, dark, tired night. (Idea - turn off the engine!)
The problem was that by the time I removed the alternator in Jasper National Park in Canada, drove to Salem, Oregon, had the alternator rebuilt there while at the Monaco Rally, then reinstalled it, the meaning of the two pieces of tape that I had put on one of the two small wires became fuzzy and confused in my aging mind. I ended up putting the wrong wire on the wrong terminal. I had thus energized the field of the alternator full time for the next year when it once again failed. I had it rebuilt a second time and dutifully reinstalled it exactly wrong once again. It again lasted about a year with the field energized full time.
This time I pulled a wiring diagram off of the Leece - Neville web site (thanks to Gerald providing me with the model #), checked the voltage on the two small wires with the ignition switch both off and on and realized my mistake. The re-builder assured me that this would cause the failures that I have been experiencing.
I am coming clean on this not because I suspect that others have made the same mistake but to clarify that it was never a problem with the quality or durability of the alternator. This one was just very unlucky when it was assigned an owner!
Bruce