Thread: Where to start looking for cause of dead battery.

I just put a brand new Everstart Maxx in the 93 SE-R two days ago. It died yesterday, but jumped right off. I ran the car and let it charge. It's dead again today. Where should I start, never done this before.

alternator.

Any new electronics in the car? Stereo?

Make sure the alternator is actually working. If it is do the following.

Remove the negative cable from the battery. Connect one side of a test light to the negative post of the battery, and the other to the negative cable. If it lights up you have a draw. The brighter it is the bigger the current draw. Turn off the dome light and have the key turned off. If you still have a drawer start pulling fuses until it goes away. The last fuse you pull is the source of the draw.

i would say alternator, but you could be having a electrical issue that is drawing current from your battery with the car off.

Yeah if your killing your battery from it sitting overnight and so on you have a draw and like they said you can connect a test light or put a multimeter between the positive post to the terminal. Meaning disconnect either the positve or negative terminal on the battery and connect a multimeter inline on Amp setting and see how many amps are being drawn. You should have very very little amp draw such as in the .02-.03 range as you will have some amp draw from the clock and other little things like the ecu backup power and so on. But you shouldnt have much more than that.

If you have more than .1 amp draw then start pulling fuses to isolate the problem. Whatever fuse you pull that takes that draw away then that is your problem.

No new electronics in the car. It was holding a charge just fine when I parked it 8 months ago. Could sitting for so long cause a problem?

If he jumped the car and it idled and ran fine, then it should not be an alternator. If it wasnt charging, then the battery would go dead almost right away and then the car would die.

I would do what ashton said and start pulling relays/fuses.

Problem solved, realized the brake light switch under the pedal was sticking. Still going to exchange the battery though since it's now been deep cycled twice.

Oh, that one sux. It happened to me before. Drove me crazy looking for the problem (during the day, lol) then someone told me my brake lights were on one night. The little rubber bumper on the brake pedal for the switch was so old that it just crumbled up and fell out.