Last year, I had an alternator go out while enroute to a campground. I keep a close eye on my gauges when I travel and I noticed the amp gauge was much lower than normal. Since my mobile mechanic doesn't live too far from the CG I was enroute to, I decided to try to make it to my destination (while on a Los Angeles freeway, no less!).
Well, about a mile from the CG the engine started to die and I knew the voltage was getting too low to sustain it. I just barely managed to pull over to the side of the freeway and called Good Sam Emergency Service. While waiting for the service to arrive I had a brilliant idea. I got out my jumper cables and connected the coach battery directly to the start battery (very carefully, of course). This arrangement gave me enough power to make it to the CG (the Good Sam driver followed me to be sure I would make it). The next day, my mechanic came to the CG and installed a new alternator.
I was grateful that the breakdown happened when and where it did. I could have been out in the desert somewhere and would have had to be towed to an unknown repair shop for service. I much prefer my personal mechanic ;)