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My cars battery dies every 3-4 days ... help!

background:

its a 2000 chevy blazer it has 99k miles i just bought it from a private seller. I have no engine problems the car runs great and strong. on the third day of having it the car was dead so we jumped it and drove to walmart to replace the battery. the previous owner may have crossed some of the wires, exaple: my head lights open my rear hatch, my radio can stay on without the key in the ignition, etc. so after replacing the battery the car died again i had the starter, battery and alternator tested they were all great. then the car dies for a third time so i have the alternator, battery and starter tested again and what do you know the battery has now been drained in a one week span. so i go back to walmart and replace the battery within 3 days it dies again! so i took it to an auto electric shop and they werent able to find any draws, so they sent me home with it and it died again. i now have it at another mechanic and he also cannot find a draw. he has taken out the alternator and inspected it there were no issues so he put it back. this car dies every 3-4 dies im sure of it. also at one time i believe the previous owner had installed a stereo system which is no longer connected… somebody please help me!!

Your headlights open the rear hatch? That is suggestive of a wiring problem. Do the headlights work at all? Was the auto electric shop at least able to fix that problem?

You are describing a classic case of an electrical fault…You MUST sort that out first as no battery has any chance of living a normal life in a vehicle with n elect prob.

If you have a 12V multi meter…you can measure the Amp draw by removing the neg batt terminal and put the meter between it and the batt…notice your amp draw…then start pulling fuses in your fuse box or under hood and see which one makes the draw lessen…if you find that…you just found the circuit with the draw on it.

Try to find that drain yourself…I am doubtful that the guys you took it to devoted the proper amount of time to find it as it can take a long time. They didnt really search for it as there was little to no money in it for them and it was all time and diagnostic effort to find the cause…these can be tricky at times to find.

Go on the net and look up the procedure I talked about it has been written up many times. only YOU will devote the time needed to find this issue I think. Let me know if I can help further.

You need to take it to a shop that can check for a parasitic current draw without disconnecting the battery. Because if the parasitic current draw is caused from a computer/module that fails to go to sleep, disconnecting the battery forces that component to go to sleep so there’s no way to determine what’s causing the current draw.

Instead, take it to someone who knows how to check for a parasitic current draw by measuring the voltage drop across the fuses.

Tester

the headlights have an automatic sensor but they are always on as long as the vehicle is started. and no they didnt fix anything i just wanted them to find the main problem

i agree with you completely. i will talk to the guy who has my car now and tell him about this and see what he says. if he wont do it then i will. thank you

I have a 2000 Blazer and it does sound like the previous owner butchered the wiring. A couple of thoughts.

To turn off the Daytime Running Lights (DRL), press the dome light override button 4 times. This disables/enables the DRLs until the next time the truck is started.

Check that the interior and underhood lights are going off with the doors and hood closed. There are roughly 10-12 interior lights in the Blazer, at 1 amp current draw apiece, they can run the battery down quickly.

Has the battery been properly charged, voltage should range from ~11.9V (fully discharged) to ~12.7V (fully charged).

Is the car only driven every 3 or 4 days or does it start for the first couple of days, then fail on the 3rd or 4th day of use?

Does the battery have an insulating blanket. It’s pretty tight under the hood and the engine heat kills batteries fairly quickly (every 2.5 to 3.5 years).

Try an find an old fashion independent mechanic that can actually troubleshoot, ask friends, family, and neighbors for recommendations.

Blackbird’s suggestion to hook up an ammeter to the battery and pulling fuses to determine current draw is a good one. It’s time consuming (i.e. expensive), so it’s something you might want to try.

Ed B.

we have been checking all the different lights in the car to make sure they are all turning off properly and whether or not they work. I am currently on my third battery and the guy that is working on my car is a family friend that builds and repairs cars, so he’s learning as he goes as well. he did take the battery out and charge it a couple days ago. i have been looking at the internet and reading alot on people who have similar problems just for ideas… the one that catches my attention the most is with the stereo… this person had the same problem with the vehicle dying every 3-4 days (which i drive the car everyday by the way) so she had her car tested and found the stereo was draining the battery so they took out the stereo and the problem stopped. im going to suggest this theory to my mechanic as well as testing the fuses. hopefully we get somewhere with this

Yep you have a drain somewhere. First thing I would do is pull the fuse for the automatic lights and any other fuses providing power to funky systems and try that to isolate it. I have had trouble before with the automatic light modules after some years. I have had two parasitic drain on two different cars and neither was easy to find. On the one after going through what you went through, I happened to go out in the garage and noticed the interior lights were on. Turned out to be drain from the door handle that turned the lights on. Pulled the wire and all was fine. The other turned out to be the electronic control module for the air suspension system intermittantly shorting itself out and draining the battery. Any time you get a few years on these kinds of electronic components,they can start to cause problems.

I had the same problem and finally after searching and talking and looking found out this, your alternator has a diode and if it goes bad you can jump you vehicle and it will charge your battery but once u turn it of the diode will still try and charge and will drain your battery, so finding that out i went and replaced the alternator and problem solved, not saying this is you problem but it worked on my truck, anyways hope this may help nd good luck.

1 Like

Danny , you replied to a 9 year old thread . I think the problem has been solved by now.