What is happening here? (battery, starter, etc.)

__amanduh

__amanduh

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Location
Indianapolis, Indiana, USA
Background: Purchased '06 TJ Unlimited this past September; 108k miles, two previous owners. New Duralast AMG battery in Sept '18, as well as other parts. Had the issue with the MFS/fog lights earlier this week, and had a drained battery overnight after forgetting to use the little turn signal trick. Zero power in the morning; not even headlights worked. Had a buddy to come over to jump; could get power for headlights, etc., but would not start. Removed and tested battery with multimeter (5.3V), hooked it up to charger/maintainer over night, tested again in morning: 12.39V. Hooked back up to TJ this morning, had power to lights, dash, etc., would hear a single click, but would not start. Didn't test individual starter relay switch, but did switch with fog light relay switch, and didn't help (doubt both of them would be bad). Even tapped on the starter a bit with a hammer, in case it was just a stuck solenoid. Still same result. Tried a third time, and the 10sec attached video is what happens... Why are the gauges going nuts, and the sounds coming from under the hood? The TJ got rained on the other night with the top completely off, as I couldn't get it into the garage and ran out of time to put the top back on before the rain. About to order a new starter, but want to be sure it's not a different electrical issue...

UPDATE: Battery is maintaining 12.09V when trying to start the Jeep. But I hear a weird, almost slight ?grinding? sound near the battery when trying to start it.

 
I would start by pulling the terminals off the battery and cleaning them. Even if you've done it already.
 
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You probably killed the battery, take it back to the store and see if they will warranty it. Most batteries don't like getting drained like that, sometimes they come back, and other times they don't.

How good were the jumper cables? Nice thick leads or cheapo thin type?

How long did you leave the cables on before trying to start the Jeep? Was the other vehicle running during the attempted jump start?
 
I'm thinking you killed the battery as well. Take it back to the store and have them load test it. They'll warranty it in most cases.
 
Can I ask what the thinking is behind the battery being no good? If it’s holding voltage while trying to start the engine, wouldn’t it still be good? Learning, here! :) That was the goal of buying a Jeep, anyways. And also, ya know, all the fun stuff, too ;)
 
What would have *killed* the battery, though? Just it being drained from one fog light left on overnight...? If that's all it takes to render a battery useless, that's a bit ridiculous.
 
__amanduh said:
What would have *killed* the battery, though? Just it being drained from one fog light left on overnight...? If that's all it takes to render a battery useless, that's a bit ridiculous.
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Take it back and have them load test the battery. It can show voltage but drop with a load, If bad should be able to get it replaced.
Eliminate the variables and start with the ez stuff!
 
Farmergreg said:
Take it back and have them load test the battery. It can show voltage but drop with a load, If bad should be able to get it replaced.
Eliminate the variables and start with the ez stuff!
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X2 to the load test recommendation. First, your 12.3v is indicating your battery is not fully charged, it would read 12.6 fully charged. I'd first put the battery on a full-size bench charger overnight. Not just a couple hours, overnight. See what the battery tests in the morning, see if it's 12.6v.

If it's not 12.6 or if it is and you have subsequent problems take it to a battery shop and have them perform a load test. A load test places a heavy load on the battery, much like a heavy-duty starter would, for a minimum of ten seconds at which point its battery voltage is measured. Its voltage after a heavy ten second load will tell them/you if your battery is good or bad. Measuring with a volt meter isn't the same and won't tell you if it's good or bad. A nearly dead battery can still indicate 12 volts with a standard volt meter.
 
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Jerry Bransford said:
X2 to the load test recommendation. First, your 1.3v is indicating your battery is not fully charged, it would read 12.6 fully charged. I'd first put the battery on a full-size bench charger overnight. Not just a couple hours, overnight. See what the battery tests in the morning, see if it's 12.6v.

If it's not 12.6 or if it is and you have subsequent problems take it to a battery shop and have them perform a load test. A load test places a heavy load on the battery, much like a heavy-duty starter would, for a minimum of ten seconds at which point its battery voltage is measured. Its voltage after a heavy ten second load will tell them/you if your battery is good or bad. Measuring with a volt meter isn't the same and won't tell you if it's good or bad. A nearly dead battery can still indicate 12 volts with a standard volt meter.
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Great explanation Jerry!
 
The clicking is a sign of low voltage. Also if the problem persists, while checking voltage when attempting to start, check voltage at the battery posts and on the cable/terminals as well. If you have a bad connection at the battery, the voltage on the posts may not drop since it becomes an "open" circuit.
 
pagrey said:
The battery tests 12V when trying to start as clearly stated in the OP. The battery is fine, you are wasting this guys time.
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Not if he is checking voltage on the battery posts themselves and the terminals are dirty. Dirty terminals create an open circuit. battery will not drop voltage if it has no where to send power too. Need to check voltage on the terminals as well as on the posts when trying to start.
 
A battery that is at 12.09 volts static is not in good condition to begin with. The problem may lay elsewhere, but one should rule out the easy checks first.
 
Gollywomper said:
A battery that is at 12.09 volts static is not in good condition to begin with. The problem may lay elsewhere, but one should rule out the easy checks first.
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__amanduh said:
UPDATE: Battery is maintaining 12.09V when trying to start the Jeep. But I hear a weird, almost slight ?grinding? sound near the battery when trying to start it.
Click to expand...

I think this means when trying to start and not static because he says "when trying to start"
 
pagrey said:
The battery tests 12V when trying to start as clearly stated in the OP. The battery is fine, you are wasting this guys time.
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Possibly, but the battery has been run down very low prior and its 10 month old.
Looking at the gauges, the ECM isn't liking what's going on.
Simple fixes would lead me to try another battery.
 
Farmergreg said:
Possibly, but the battery has been run down very low prior and its 10 month old.
Looking at the gauges, the ECM isn't liking what's going on.
Simple fixes would lead me to try another battery.
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I love simple fixes too. Like @Alex01 said early on I'd focus on the cables but I know everybody has their own way of troubleshooting. I'm sure it'll get resolved soon enough, it doesn't look too messed up.
 
pagrey said:
I think this means when trying to start and not static because he says "when trying to start"
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Correct, without being there and putting a meter on the battery and terminals I am just speculating. All I do know from the video is that the ECM and starter are lacking the proper amperage to function correctly. Since the battery is not dropping excessively low, there must be an open preventing the amperage from getting from the battery to the component. 99% of the time it is a battery terminal/cable issue.
 
__amanduh said:
What would have *killed* the battery, though? Just it being drained from one fog light left on overnight...? If that's all it takes to render a battery useless, that's a bit ridiculous.
Click to expand...

Discharging a standard car battery past about 10v is really hard on it. There are deep cycle batteries designed to come back from deep discharges where a standard battery is not. I don't know exactly why but something changes in the battery and they will usually not be the same after being discharged that deep. Sometimes you can bring them back for a while but their lifespan is usually shortened tremendously. I just replaced the battery in my wife's honda civic for this reason. Not only was it a cheap autozone battery but it had been deeply discharged numerous times. I've brought it back quite a few times but it finally gave up and wasn't holding a charge any more.

https://www.lifewire.com/car-batteries-are-made-to-die-534765
 
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