OK my poor girlfriends battery in her car died the other day, so we went and bought a new one, been fine for several days now and bam its dead again today, we are 100% sure we did not leave any lights on, so what the heck is going on? Any one have any ideas? Please let me know! thanks!!

 

anyone?

 

have you checked the alternator? kragen or autozone might be able to check the charging system in her vehicle on the spot.

 

I had a similar problem with my Honda. I turned out to be a short in the stereo wiring leading to the amp. My Mustang was also draining the battery and that turned out to be a bad fuel pump (stayed on when the car was turned off). Good luck.

 

you can also get a volt meter and measure the voltage across the battery terminals with the car running. it should read like 14.2V. then turn on the lights, the radio, high A/C blower fan, and measure the voltage again. it shouldn't change.

double check your glove box, ash tray, trunk light, etc aren't on even though the interior lights are off.

you can also test if something is drawing current when the car is parked by setting the voltmeter to measure amps, then putting the voltmeter in series with the negative terminal of the battery and the wire that connects to it. i didn't know my glove box light was the thing draining my battery and with the car parked, it drew .130 amps. when the glove box light was off, it drew .030 amps.

oh yeah, there might be a chance your "new" battery is bad. when i bought my battery, i pulled it off the shelf, and measured the voltage across the terminals. it was 11.7 or 11.3... something ridiculously low. I told the employee, showed him the voltage, then kept on measuring batteries until i found one that had over 12V.

 

Thanks guys, yeah we took it back to Autozone where we got the battery, Alternator is fine, and you know what onebadfyvo, i think it might be the radio, she has had problems with it ever since, it usually will not turn on, i suppose we will take it somewhere this week and have it looked at..

also check the fuel pump just in case..

 

OK i got this voltage tester and when the car is off i touched the tip of the tester to the spot where the fuse for the radio goes, and even when the car is off it is still getting power, along with 3 other fuses in the box, i assume they should not be getting power when the car is off.. The other 8 fuses or so do not get power, just these 4(including the radio)..