I have a 2001 Monte Carlo thats battery drains overnight. I jump start the car in the morning and its good for the day but the next morning its dead. I bought a brand new battery and still have the issue so I got the alternator tested at Auto Zone and they said the alternator is fine. I have no other ideas... I noticed the alternator was making a slight whine noise so what I am wondering is should I buy a new alternator even though Auto Zone said its ok?