Lets test both the battery and alternator:
Battery: Take it to any store that sells new ones other than Auto Zone and ask for a free 15 second load test. This quick test will find the reserve amperage capacity. Amperage spins starter motors not voltage.
Alternator: When a good battery starts the car touch the battery terminals with an inexpensive volt meter set @ 20 volts with the engine running. IF the alternator is charging properly, the volt meter will read between 13.5 - 14.2 volts.
Get the vehicle running take the positive post of the battery off. If it stalls the alternator is NFG
Most likely the battery. Places like Advance Auto Parts will test batteries and charging systems for free.
If it were the alternator, you wouldn't have been able to drive the car for ten minutes. If you had a bad alternator and a dead battery, there would be no power to run the engine.
If you drove it for 10 minutes and it wouldn't start back up its probably the alternator. the battery should have charged enough by then to start again
My car is a 1996 Mazda 626 es. Today when I went out to start it, it wouldn't start. The battery was dead. I know this because nothing came on. No lights etc. I hooked it up to my jeep and got it running. Then I drove it for around 10 minutes and I shut it off. After 30 seconds MAX I tried to start it again and nothing. I heard it trying to turn over but it sounded very weak. The lights (dome,door,dash) all worked but dimmed when it was trying to turn over. They eventually died. So my question is: Is it my battery or my alternator? I think it is the battery because it was dead when I tried to start it. I don't think I left any lights on that would have drained it. I also think it is the battery because when I hooked it up to my jeep to charge the battery (I did that for like 10 minutes) it started fine when I tried to start it because it was hooked up I guess. It ran fine for the bit I drove it. Which is another reason I think it's the battery over the alternator because if the alternator was dead and the battery had a charge the car would have died pretty quickly because it was running of the battery since the alternator wasn't charging. Please tell me what you think is the problem. I would love to hear everybody's opinion. I know this is long but I tried to give as much info as possible :)
