sooo just got back from vacation and had a dead battery--started the car with booster pac, drove to the parts store had them test the battery and the alternator this is what they said---the battery (obviously) wasnt throwing any juice out to even test then when they tested the alternator it threw out 13.9 volts (very good) and only 13 amps...from what i hear it should throw like 80-100 amps?? so im starting to think they are both dead cuz the battery only holds a charge for a matter of 20-30 minutes or lessss but the alternator also isnt doing much either...what do you guys think....if i had to pick one of them to be bad it would be the alternator but lemme kno what yall think

 

If you hook up a volt meter while car is on and you get voltage of above 13.0 and when you rev engine it climbs a bit your alt should be ok. If the alternator is not working your car with lights on should shut off within a 1hr or less of driving since its runing on the battery. You have to understand that the battery is only used to start the car, once started the alternator powers the whole car plus charge your battery. Its seems your problem is the batt if it will not start but once it does runs with no issues. Also check your terminals make sure there is no corrosion. If you need a batt get a Red top Opitima gel batt, they will outlast anything in the market.

 

+1 on optimas. Also it'll take less than an hour to kill it. you'll notice certain electrical things start to go dead while you are driving. mine did that and died right when i pulled into autozone.