Ok im getting really frustrated and its pissing me off. If i get my battery charged at auto-zone it works fine and runs and everything everything charges but if i let it sit over the weekened it seems to loose all power and wont start. I got battery charged sunday drove to school monday-friday 2 times a day. Saturday drove to school parked it for 8 hours started like a champ. Sunday went to go to church *DEAD*. Jump start it today drive to school. Check volatage 12.5(thats were it usually is sometimes 13 never really below 12) Shut car off. Come back to car try to start, *Click*. Is this a grounding issue or a alternator issue. That battery is only like a month old. Is this a alternator problem or a grounding issue? BTW its a 86 Base Model.

 

You know, that auto zone can diagnose your alternator too. Usually, when the motor is off, the battery voltage (measured across the terminals) is somewhere in the 12-12.5 range. Once the car is started, that voltage should jump to 13.5 or so.

 

does it lose volts while your driving the car?

 

If the alternator is bad, the car is only getting battery power and that will drain rather quick.