I've posted this several times before over the years but I'll post it again
after another example has just been discussed.
About 80% or more of "bad alternators" are actually just the brushes being
worn out.  I was assured of this many years ago by a guy who was making a
very good living with a rebuild shop, doing alternators, starters, and at
that time generators.  Many of you saw my post back in February titled
"Don't Leave Home Without 'Em" and the picture I posted at that time:
*http://tinyurl.com/cog5go*
I'm glad that John is back on the road.