97 pontiac grand prix v6 3800 motor. The car battery will not charge. Battery is new and had altenator tested at auto store, tested as good. The car will jump start just fine. But then battery looses charge after awhile. Battery light also comes on then goes off. I had car running, disconnected battery and car did run off altenator for about 40 seconds then died. Is there an altenator sensor telling the car not to charge? Help.
Monday, February 25th, 2013 AT 10:53 PM