2004 Jetta Alternator/Battery Problems

[khrissy315]

I have a 2004 jetta that my son's been driving for the last year and a half and a week and a half ago, the car died on the hiway. He had the alternator replaced, then had to replace the battery too bc the alternator had "juiced" the battery. Got 20 miles down the road, and the car died again. Towed it home, took it to a VW repair shop, replaced the battery again. Drove about 20 mins., car died again. Told it was a "bum" alternator, had it replaced, lasted about 20 mins. again. Next told it was the wiring on the fuse block was corroded. Still not working. Anybody have any ideas???
This is an automatic transmission. I don't know any other specifics, other than it's just a "regular" model, nothing special on it.

Thanks