You didn't get that alternator at Autozone by any chance, did you?

Went through 3 on my wife's civic:

First one- Dead right off the bat
Second one- worked for about 10 minutes and died
Third one- worked for around eight months, then died after she left her lights on and had the car jumped. The Autozone lifetime warrantee didn't impress the tow-truck driver much

New alternator is AC Delco with a warrantee that covers towing

Moral of the story- Autozone bites.