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10/20/2017 1:01:18 AM
9/22/2017 12:11:25 AM
Posted: 8/24/2005 4:10:33 AM EDT
My car's battery has been acting up this past week. Harder and harder to start, its almost to the point where it might not. It's a 2001.

Is there a good way to tell if the battery has just lost it, or if there may be something in the car that is slowly draining the battery when it's off? The alternator's fine as the lights don't dim at all and there's plenty of juice when the car's running.
Link Posted: 8/24/2005 6:30:13 AM EDT
Normal battery life is 4-5 years, it's probably dying. Now is a good time to replace it, just before winter and it's comfortable working outside.
Link Posted: 8/24/2005 6:43:49 AM EDT
Take it to Autozone or somewhere that offers free load testing. They'll check it out for you. A quick way to get a good idea is check the battery with a voltmeter when the car is off, it should read about 12 volts. With the car on, the battery should read around 14 volts since it's being charged by the alternator. I'm not sure you can check amps without a load tester. Anyway, take it to Autozone. You don't want to be in the middle of nowhere in the dead of winter when the battery decides to give up. MJD
Link Posted: 8/24/2005 6:57:29 AM EDT
[Last Edit: 8/24/2005 6:59:46 AM EDT by goodmedicine]
To check the battery for a drain when just sitting.

Make sure eveything is turned off on the car

Take the neg. battery wire off the battery.

Put a volt meter or 12vdc test light between the
neg. battery wire and the neg. battery post.

If the meter indicates or the test light, lights up then there is a draw
on the battery.

If there is a draw, start pulling fuses one at a time, if the test light stays on put it back in.
Keep going until test light goes out. That will be the curcuit that is drawing current.


GM
Link Posted: 8/24/2005 7:17:55 AM EDT

Originally Posted By goodmedicine:
To check the battery for a drain when just sitting.

Make sure eveything is turned off on the car

Take the neg. battery wire off the battery.

Put a volt meter or 12vdc test light between the
neg. battery wire and the neg. battery post.

If the meter indicates or the test light, lights up then there is a draw
on the battery.

If there is a draw, start pulling fuses one at a time, if the test light stays on put it back in.
Keep going until test light goes out. That will be the curcuit that is drawing current.


GM



I just took it to a battery shop... that's what happened. Something's drawing down my amps. All lights and everthing are off.

Looks like I'll have a fun time pulling fuses tonight.
Link Posted: 8/24/2005 1:39:19 PM EDT
Crap.

Just spent an hour taking each fuse out one by one, under the hood and in the passenger compartment. Had the multimeter set to 15 DCV, and it was showing around 12V between the negative post and the negative wire. It stayed at 12V through all of the fuses.

I don't know what to do now...
Link Posted: 8/24/2005 2:33:59 PM EDT
Link Posted: 8/24/2005 4:43:37 PM EDT

Originally Posted By DDiggler:
Crap.

Just spent an hour taking each fuse out one by one, under the hood and in the passenger compartment. Had the multimeter set to 15 DCV, and it was showing around 12V between the negative post and the negative wire. It stayed at 12V through all of the fuses.

I don't know what to do now...



The instructions are slightly off:

Do what you did above, except make sure your multimeter reads current, in amps. What you're looking for is current draw with everything off. Connected as you did, you completed the circuit and you were measuring voltage.

Make sure the multimeter will read current, in amps, and have it on the highest setting it can go. Try not to open the door, don't try to start the motor or anything that will draw power, because you'll probably blow the multimeter fuse.

BTW: if you do go to the local Autozone/Advance Auto/etc. (they'll all test your battery for free), make sure the battery is charged up by putting it on a charger overnight or all day. The test won't work if the battery is low. Just cause it can start the vehicle doesn't mean the battery is charged.

Hope this helps.

Merlin
Link Posted: 8/24/2005 9:06:20 PM EDT

Originally Posted By DDiggler:
Crap.

Just spent an hour taking each fuse out one by one, under the hood and in the passenger compartment. Had the multimeter set to 15 DCV, and it was showing around 12V between the negative post and the negative wire. It stayed at 12V through all of the fuses.

I don't know what to do now...



That can happen buddy, all is not lost.

12vdc is a tricky bastard.

What that is telling you, perhaps, is that the drain is happening before it ever gets to the fuse panel.

That usually involves "main" wiring but not always.

I wish I could be more help "online" but it is something you can only diagnose in person, if that.

Keep working the problem from the source back.

Keep eliminating possibilities the best you can, good luck!!

GM

Link Posted: 8/24/2005 9:43:53 PM EDT
You need to measure the current as a previous poster said. With all the electronics in the car there is always a small drain. (think...what keeps the clock running, the radio stations in memory, engine and transmission computers) If it is several amps, keep looking. Check your owners manual...my car has fuses/breakers under the dash and under the hood. The car may shift or run a little strange after you disconnect the battery until the computers relearn how you drive.


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