Left car headlights on for 4 hours. Car is dying randomly after jump starting?
1995 Ford Mustang GT. Five days ago left headlights on for 4 hours. Car wouldn't start and had to be jumped. Drove for 10 minutes with the a/c&switching radio stations and was fine. Then I turned around and second I roll windows up car died. Had to be jumped again. Then I let it idle for 30 mins so alternator could charge the battery. Drove fine for 3 days only drove a few miles.Yesterday I start driving it dies again. I tried to restart it and the engine would turn over a little bit and start barely but then die. After 6 attempts at this it starts fully. Battery tested by AAA today and the voltmeter was in the red area indicating I needed a new battery. Then I also got it tested at Autozone (I trust a computer more than AAA needle voltmeter) and it came out fine at 12.47 volts. Battery was good. The battery had plenty of voltage when it was checked so isn't the alternator doing its job right if the battery was low on power from leaving lights on? And when turning the ignition to the right (not turning car on) the battery and check engine lights stay on and the voltage gauge dips to the left towards the negative end. Then when the car turns on voltage gauge stays in the middle like normal and check engine/battery lights go away. What does this mean? Is battery really bad and Autozone was wrong? This all started popping up after leaving lights on. Today after putting the battery back in it started and drove fine for about 40 yards until I parked it somewhere else.
Added (1). Also this is more of a problem of keeping the car running, once it is started compared to just starting it.
