"Hi! I have a 2001 Ford Mustang 3.8L and for 2 weeks the battery light has been on...The battery is brand new about a month ago I got it and the alternator has been running fine. Today the battery died and the car even died while I was driving home...soon as I jump it it makes a weird noise like a siren pitch from a fire truck but not too loud if you understand. .. anyways I pushed the window button to roll the window up and then the engine stalled and battery died. . I'm hoping this can be a easy fix...not sure what to do

 

Sounds like the alternator has failed, go to a local parts house like Autozone and have them test the battery and alternator and check them both out.

 

I am 95% sure your alternator died. If the battery light is on, you should put in a new alternator and make sure you check your wires for corrosion and exposed lines. Check the terminal too. I had a problem with corrosion on my battery. If you have an AutoZone near you, get a terminal brush to clean it.