Battery dead after 2 weeks

[ben92126]

Hello. I wonder if anybody could help me with my problem. I have a 1995 Camaro 3.4L and after driving the car from California to Washington state (1200 miles), I left it at a friend's house for two weeks. My friend said that he started the car and left it running for about 10 minutes a couple of days after I left, then two days after that he did it again. He was unable to start it for about 4-5 days, then when he went to start it up, it wouldn't start. I got back to Seattle after 2 weeks and tried to jump it with my truck battery. That didn't work, so I took the battery to Autozone and they recharged it for free. Installed the batttery and the car started right up. Battery is about 2 months old. My question is, why jumping the battery to my truck did not work? The truck engine was running when I tried to jump the car. Also, I know there is a draw in the system, I just don't know where to start looking. I have a manual fan switch, an aftermarket headunit as far as non stock electronics. Manual windows and door locks. Where do I start? Thanks for inputs.

[Rob Bell]

Re: Battery dead after 2 weeks

Well as far as jumping it, if the battery was totally dead, it may take a while longer than usual to get enough of a charge for it to work. So the question becomes, how long did you leave the jumper cables hooked up?

With the current draw that you know is there, you need to hook up a multimeter set on Amps to measure the current draw when the car is off. You hook up the leads in series between the battery terminal and the battery cable. Now you will see how much current is being drawn. If it's more than, say, 100 mA you've got a problem. There will always be some draw because of the clock, computer, radio, etc.

So, now that you have the multimeter measuring current draw, you start pulling fuses one at a time until the reading drops way down. Then you have found the problem circuit, and then you have to diagnose from there. If none of those works, disconnect the + cable from the alternator. Sometimes when the diodes in the alternator die, you get a short. Actually, if you have a current draw in excess of 1 amp I would start with the alternator. I had an alternator die once and it was drawing 2 amps. It was enough to run the battery totally dead in one night.

[blindeyed]

Re: Battery dead after 2 weeks

My guess would be the alternator, take that out and have it tested at AutoZone as well. It's really easy to take out, especially on the 3.4's.

[hockeyman]

Re: Battery dead after 2 weeks

Well as far as jumping it, if the battery was totally dead, it may take a while longer than usual to get enough of a charge for it to work. So the question becomes, how long did you leave the jumper cables hooked up?

With the current draw that you know is there, you need to hook up a multimeter set on Amps to measure the current draw when the car is off. You hook up the leads in series between the battery terminal and the battery cable. Now you will see how much current is being drawn. If it's more than, say, 100 mA you've got a problem. There will always be some draw because of the clock, computer, radio, etc.

So, now that you have the multimeter measuring current draw, you start pulling fuses one at a time until the reading drops way down. Then you have found the problem circuit, and then you have to diagnose from there. If none of those works, disconnect the + cable from the alternator. Sometimes when the diodes in the alternator die, you get a short. Actually, if you have a current draw in excess of 1 amp I would start with the alternator. I had an alternator die once and it was drawing 2 amps. It was enough to run the battery totally dead in one night.

Very good advice! I'll be testing my minivan's output using this method, once the weather clears/warms up. The battery went on me this past september when I was about 100 miles from home ...in the middle of friggin' nowhere! I replaced the battery and it seems to be just fine ever since, but I'd like to make absolutely sure.

[ben92126]

Re: Battery dead after 2 weeks

ok update to my problem. i did this:
took out negative battery cable from battery terminal.
set multimeter to read amps/dc.
connected a multimeter in series between negative battery terminal and negative cable.
multimeter read 4.51
started taking out fuses, first fusebox inside the car, then fuse box in engine compartment, no drop in reading. started taking out relays, same result.
took out positive battery cable from back of alternator, no drop in reading.
i took out the fuses one at a time, read the multimeter, then put the fuse back and did this to all the fuses, one at a time. no drop.
could it be that more than one circuit is drawing current? i did not want to take all fuses out at the same time as i might not remember which one goes to which socket. once i get my digital camera, i will take a picture of the fuse boxes and take them all out at once to see if there is a change in readings. i am assuming that all electrical circuits in a car are fused, right? so by taking out all fuses, i should get a drop in amp draw. any suggestions welcome. tia.

[Rob Bell]

Re: Battery dead after 2 weeks

Holy cow, it's drawing 4.51 amps? If that's correct I would think the battery wouldn't last more than a couple of hours. You were doing the fuse pulling correctly. It has to be one at a time because you have to know what each individual circuit is doing. If multiple circuits were drawing excessive current, you would still see a pretty good drop when one of the fuses was pulled. Try pulling off that plug on the back/top of the alternator. I think that's what provides power to the stator. The only other thing I can think of would be that maybe the starter solenoid is drawing some current. Maybe not enough to engage the starter, but enough to drain the battery. I'm kinda shooting in the dark now, though. I really have no idea what to do beyond the fuse-pulling circuit test. I hope someone else can chime in with an idea.