We’re sorry to hear this happened to you. Here’s a rundown of some of the issues that might make a new alternator go bad, or stop working:
We strongly recommend calling the mechanic who did the initial alternator replacement and asking what could have caused this issue, and if they have any quality guarantees or warranties. Some mechanics will fix the issue free of charge.
If they won’t do that for you, call around to other mechanics in your area and tell them what happened, being sure to explain that this would be your second alternator. Shop around for good prices, too. That’s always a good idea whenever you need a pricey car repair.