2010 Dodge Grand Caravan
I’ve pulled each fuse from box and tested battery and it continued to pull 12v.
Any ideas what I can check?
Thanks
Bob
Are you measuring the voltage on the battery posts?
Tester
I am not sure what the question is exactly. A battery in new condition should be putting out 12.7V with nothing connected to it so I think you might be checking at the posts as suggested above. If so, something above 12V sounds normal.
A battery supplies a voltage, a load draws (some say pull) a current. Only being dead makes a battery not-supply a voltage. Do you mean that something is drawing a current when the van is off? The clock in my '87 pickup draws 6 mA all the time - an amp-hour/week. Something is probably pulling some current in your van all the time.
I disconnected the negative cable and test from negative post to negative cable. Battery dies over night
Yes something is pulling current and I can’t figure out what. I’ve pulled every fuse and it never stopped pulling current.
It’s enough to kill the battery every night.
Or is the battery the problem? If it has caps and you have a hydrometer, test the specific gravity of each cell. Are you charging it up with a battery charger? Test it after a long slow charge and then the next morning. Or take it somewhere to be tested. Walmart and most parts places that sell batteries have an electronic gizmo that quickly gives a more thorough analysis than a voltage measurement.
Have you disconnected the alternator and tried this test… That’s the only thing left hooked up…but if the negative cable is off the batt my theory goes out the window.
What you are telling us is that your battery is isolated by itself and is still dying…which means your battery has bought the farm. How old is this battery?
If your neg cable was still hooked up…I would again look to the alternator.,
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Ok let’s see if I can clear things up.
Beginning:
Van won’t start in the morning. I jump it and it starts right away. Let it run for a bit and then it’ll start every couple of hours. Next morning same thing. Repeat for a few days.
Every morning battery is dead.
Bought a new battery. Same results.
I disconnected the negative cable so the battery won’t die. Using a voltage tester if I touch the negative post and the negative cable I’m getting a reading almost 12 being pulled, with everything off in the van.
I’ve pulled every fuse one at a time trying to find the circuit that is pulling juice. No luck there. I’ve disconnected the alternator, no luck there.
So I’d pull a fuse, retest Neg-post to Neg-cable still pulling 12.
You have to measure the amperage, not the voltage.
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This tells you that the battery is working, not that a current is being pulled. @NYBo tells you right: measure the current being drawn in the configuration you describe.
If you disconnect your battery and it won’t start your car in the morning then your battery may be fine but something is making your car hard to start. My fuel pump wore out; one of the symptoms was hard starting, for example.
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I’m trying to figure out what is draining the battery when the car is off
Google “perform parasitic draw test”
as the others already said, you have to measure current draw, not voltage
any aftermarket stereo or alarm?
the culprit could also be a control module
by the way . . . even fuse boxes are considered control modules nowadays
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Check any courtesy lights like the glove box or under hood light.
They should all be off, butas soon as you open the glove box …for example…a switch will turn on that light.
Open the glove box and remove any cover from the bulb. Close the glove bow and wait 2 minutes. Then open the glove box and touch the bulb ASAP. If it is hot…that light is not shutting off.
Do the same with under the hood.
Also check that a cargo light was not left on.
Yosemite
@Randomtroll is right, when you put the volt meter between the negative terminal and the disconnected cable you are basically checking the voltage of the battery. Plenty of stuff, like the cars computer, radio etc draw a tiny amount of current when the car is off. The voltage is 12 but the current is very low. Google parasitic draw, for example - https://www.youtube.com/watch?v=KF1gijj03_0
I had a parasitic draw once. I removed the fuses 1 at a time until I figured out which circuit it was. Everything on that circuit worked properly. I cut its wires 1 at a time and figured out that the short was for the light in the glove compartment, which my pickup lacks, but which the Forerunner, which uses the same wiring harness, has, so I could leave it cut before the short. If you’ve taken out every fuse but still have a current - I don’t have an idea other than a short inside the battery - does that happen anymore? But you’ve tried a new battery.
Measuring the rate of draw is the first step.
Be aware that many circuits are protected by a PTC device, no fuse to remove.
The load shedding feature will switch off power to all of the interior lights after 10 minutes, the glove box, vanity lights and cargo lamp should not discharge the battery. Do these vehicles now have under hood lights? I have not seen that since the 1980’s.
Make sure the battery is fully charged and then disconnect the heavy power lead that goes to the alternator. Do your same test… Start the vehicle once or twice and then shut it off and wait till the next day and see if she starts up without issue. If it does, you just found the culprit. You can figure all this out with a voltmeter as well, but the disconnect is pretty straight forward and easy to do. If she does not start the next day…the culprit is somewhere else. When alternators drain the battery, they will be warm to the touch when the engine is cold which is another big clue… But for simplicity, do the test outlined above, cant hurt anything by trying it and it will be proof positive to see if the alternator is the problem…or not.
Easy test to perform…
One caveat… If you do unhook the positive lead from the alternator for this test, be sure it does not contact any metal…you can tape it up or zip tie it out of the way or both to prevent it from grounding out. Shouldn’t be difficult to safely isolate the connector at the end of the positive wire to the alt.
I don’t know about your van, but my pickup has 2 fuse boxes, 1 in the cab, 1 under the hood.