I have a 2003 mustang...It was working just fine yesterday. Then we got into it and after driving about a mile the battery light turned on, on the instrument panel. It drove fine for about 20 minutes, then suddenly the battery gauge started going down and my instument panel and headlights were very dim. I went and go the battery tested and they said it was bad. So I got a new battery but on the way home it did it again. I turned the car off and now it won't turn on. Please help me what can this be???
