Yeah, that's a scary one. Mine went quiet too and just left me stranded. I mean, I just keep a spare in the truck now and swap it out way before the schedule says to.
Whoa, I totally disagree with swapping them out early. That's just throwing away a perfectly good part most of the time. Modern alternators are pretty solid and usually give you plenty of warning before they totally fail, like weird lights or a noise. I'd much rather just check the belt and connections regularly and wait for a sign of trouble. Carrying a spare that just sits around for years seems like a waste of money and space to me.