Recuring Alternator Issues

Hello,

A few months back my car wouldn't start, I charged up the battery, let it run for a bit and watched as it died about 10 minutes later - conclusion, bad alternator, so I replaced it.

Two months with no issues, and then it happens again. I figure - defective alternator - I go and replace it again; replace the belts too, and, for good measure, take a look at the harmonic balancer (my understanding is that a bad balancer can kill an alternator) - no wiggle.

Two weeks later. On the Road. To Canada. It dies again, in the same manner, and my dad, who is driving the car is forced to tow it to a garage, where they tell him... hey, its a bad alternator. They replace it, take his money, and he drives it to Canada and back home....

This happens again - I replace the battery. The car runs for a few weeks.
A few days ago, it happens again, and I am just about ready to push the car into the ocean....

To recap:
The alternator has been replaced several times, with varying lengths of time between replacement.
The battery and belts are new and appear in good order.
The car runs for a good long while, with no apparent problems between replacement and failure.
The car has yet to fail WHILE running.
So what is going on?

Bad wiring? Fuse? Wouldn't the car simply not work with a replacement alternator if that was the case?

Any Ideas?

Thank you.