Car Dies. Not battery or alt

[ncampos92562]

Here's the breakdown, if i let my car sit for about 10 hours, the car will have 12v and start right up. But after that the battery will die within 30min. It kills about 5v-6v during that time. It is really weird, never had a problem like this.

Battery is new(month old), I disconnected the alternator before with the battery connected and it still dies in the same time. All fuses are good.

All I can think of is a random wire somewhere, probably the alarm but who knows with these cars right? It's just so odd that it'll just all of a sudden drain rapidly and not consistently. I've never heard of a grounded wire doing this and the only thing with power while the car is off is the alarm pretty much.

Anyone got any ideas? Been doing it for about 6ish weeks. That's the reason I got the new battery, and that the last one was 4 years old. If I can't figure it out soon I'm gonna go deep into look for random wires when I change the head gasket and timing next week.

 

[2gdanny]

Here's the breakdown, if i let my car sit for about 10 hours, the car will have 12v and start right up. But after that the battery will die within 30min. It kills about 5v-6v during that time. It is really weird, never had a problem like this.

Battery is new(month old), I disconnected the alternator before with the battery connected and it still dies in the same time. All fuses are good.

All I can think of is a random wire somewhere, probably the alarm but who knows with these cars right? It's just so odd that it'll just all of a sudden drain rapidly and not consistently. I've never heard of a grounded wire doing this and the only thing with power while the car is off is the alarm pretty much.

Anyone got any ideas? Been doing it for about 6ish weeks. That's the reason I got the new battery, and that the last one was 4 years old. If I can't figure it out soon I'm gonna go deep into look for random wires when I change the head gasket and timing next week.

i have never seen any one disconnect the alternator and leave the battery, the alternator runs of the crank pulley.
have the alternator checked out autozone, pep-boys they can test the alternators, if it checks out ok then you know its not that and your battery is already new so check fuses, and most important check the grounds.

 

[luv2rallye]

Sounds like you either have gotten a bad new battery (won't maintain a charge) OR more likely have a large battery drain or short.

Testing battery: http://www.dsmtuners.com/forums/newbie-forum/258035-car-died-freeway-electrical-problems.html

Testing for drain/short: http://www.dsmtuners.com/forums/art...-partial-short-battery-drain.html#post1496998

 

[DSM1G90]

I disconnected the alternator before with the battery connected

..which will blow alternators if you disconnect the alt while it's running (if youre doing this trick to check ..) inrush from the battery blows the regulators in a quick.

Primer 101: All vehicles uses the battery to operate and the ALT is just there to keep the battery in prime condition-not to run the vehicle's electrics. If it has to, it will overload the regulator to eventually take it out. Why, you put a weak or dead battery on a charger and not let the ALT charge it up.

With everything all hooked up, start it up and take a VOM on DCVolts and touch the battery connection on the ALT with the red lead and black to ground. Output should be 13.8 to 14.3 VDC. If not, the ALT is blown.

Some batteries can be bad new. If so, return for a exchange if you got receipt papers.

 

[Ghostcrafter]

I'd honestly have to say that it sounds like a bad alternator. You stated in the title that it's not the alternator, but you didn't mention it at all in your further description.

The battery is obviously self-charging, as you stated that after sitting for 10 hours it would have a 12v charge. Therefore the battery is good.

However...

The battery is used only to start the vehicle, after that the alternator produces the power to run the vehicle and recharge the battery. Disconnecting the alternator while the vehicle is running would kill any battery in short order as the battery is never meant to power a running engine long term. The fact that the battery is running down in a short time, regardless of the alternator being connected ... points to the alternator not producing power to run the engine, therefore the engine is forced to run off the battery.



In short...

Running Engine on the Alternator = Normal Operation and Recharging Battery
Running Engine on the Battery with no Alternator = Drained Battery
Running Engine on the Battery with a bad Alternator (or cables) = Drained Battery

Get it tested, nearly any auto parts store will test it for free if you bring it in (off the vehicle).

If the alternator tests good, then move on to checking the cables for internal corrosion. It is possible for cables to corrode internally, especially in humid weather, yet appear to be fine on the outside. If there is corrosion it can get to the point that even a good alternator simply can't push the current through to the battery and the engine. I have seen customers warranty alternator after alternator (even after they'd test good), despite my telling them to check the cables as well ... only to have them eventually give in, replace the cables and fix the problem.

 

[zanderson]

I'd honestly have to say that it sounds like a bad alternator. You stated in the title that it's not the alternator, but you didn't mention it at all in your further description.

The battery is used only to start the vehicle, after that the alternator produces the power to run the vehicle and recharge the battery. Disconnecting the alternator while the vehicle is running would kill any battery in short order as the battery is never meant to power a running engine long term. The fact that the battery is running down in a short time, regardless of the alternator being connected ... points to the alternator not producing power to run the engine, therefore the engine is forced to run off the battery.

Get it tested, nearly any auto parts store will test it for free if you bring it in (off the vehicle).

He said his battery is holding a charge however. I agree it's either a battery drain, or a bad battery. I'd go get it tested. It's free and easy.

 

[Ghostcrafter]

He said his battery is holding a charge however. I agree it's either a battery drain, or a bad battery. I'd go get it tested. It's free and easy.

No, he said the Battery is holding a charge if he lets the vehicle sit, but that the Battery dies after running the vehicle for about 30 minutes.

(And for the record, a vehicle will still run without a Battery, so long as the Alternator is working properly. So if the vehicle is dying, while running due to a dead Battery ... it means the Alternator is not getting a Charge to the Battery.)

 

[zanderson]

No, he said the battery is holding a charge if he lets the vehicle SIT, but that the battery DIES after running the vehicle for about 30 minutes.

(And for the record, a vehicle will still run WITHOUT a battery, so long as the Alternator is working properly.)

Opps, reading that wrong. Probably time for bed

 

[ncampos92562]

No no no wait, you guys got it confused. I must have worded it wrong. During the 30min that it drains the car isn't running, just continuing to sit. I just have figured out the time span by now of when it drains and about how fast it does. And I forgot to mention it will drain a tad in those sitting 10 hours from like 12.2 to 11.8-9.

But know that you guys say a bad new battery, I remember I got the new battery because I had a weird stater problem(would act like the relay was bad but ended up bypassing the relay, so I got a new battery to try and fix it). That starting problem went away and then this happened. So i'm thinking a bad new battery.
Ill go have it checked tomorrow and see if they can tell if it's bad.

Thanks for the help. And I didn't disconnect the alternator when running, I know that screws alts. Just disconnected it during one of the 10 hour periods with no running of the car during this.

 

[Ghostcrafter]

Now THAT problem I had with my car when I first got it. Turned out to be the previous idiot owner wiring the stereo up wrong. It could kill the battery in next to nothing flat. I removed the stereo and the problem was solved.
I still have to address the rats nest of wires he left the car with, when I finally get to putting a new stereo in.

have 12v and start right up. But after that the battery will die within 30min.

I think the assumption came from that, it was assumed that the car was still running it started right up, .

 

[ncampos92562]

That's the thing, I already ripped out/fixed all the ghetto wiring from previous owners(oh how I loved wiring after that). I've checked all connections for alarm, stereo, wideband, pretty much everything in the cabin. And everything is hooked up correct with no random wires. I don't see how a bad wiring set up can kill a battery after 10 hours every day pretty much at exactly the same time.

So I'm betting it's the battery. I got the receipt anyway with the warranty so I should be good.

 

[ncampos92562]

UPDATE:

Not the battery. Took out the battery when I parked that car last night and let it sit. Battery was at 12.41v and then check today about 14 hours later and it was at 12.38 volts. So almost no drop with it disconnected and out of the car. Which means there has to to be a drain somewhere.

How I love electrical.

 

[ktgurl87]

that means you get the glorious job of chasing wires in the engine bay used to have an issue where we would have to jump the gst like, every single morning (after it sitting for like... maybe 12 hours) i personally blame the super awesome clippy that doesn't even clip to the starter. then we found out one of the starter bolts had backed out damn near all the way (unrelated? maybe, but who knows). replaced the terminal ends, that helped. ripped out every single piece of unnecessary wire out of the engine bay, which also helped. then i found out that we had accidentally killed the battery (i assume it was us jumping the car every morning) where the battery would drop off .1 volt every couple of seconds. so got it replaced and it seems to have fixed it. haven't had to jump it unless it sits for a handful of days. so we'll see after i get done replacing every damn thing in this car. hopefully it gets resolved. good luck with your search!!

 

[ncampos92562]

Seriously right? I'm over electrical in the car. It's like an std for DSMs. I guess I'll check all the wires running to the battery positive. The last real thing I touched with electrical was the starter and alarm. I've checked the alarm, all wires are good. But still have yet to check the jumble of wires wrapped up heading to the starter.

Oh yea, and found this thing under the passenger seat a couple weeks back. just cut it off and taped it off. I'm guessing it was to the stock stereo or something but the wires continue in that bundle and don;t come out near the radio area.

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Goes out of the carpet and T's into this bundle.

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And this is where that bundle goes.

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After that, I have no idea where to go next.

 

[ktgurl87]

that appears the be the connector for the stock amp. and that is the most god awful rat's nest i've ever seen!!

 

[Ghostcrafter]

that appears the be the connector for the stock amp. and that is the most god awful rat's nest i've ever seen!!

Clearly ... you haven't seen my car.

 

[ktgurl87]

Clearly ... you haven't seen my car.

. if yours is worse than that then i feel VERY very sorry for you. that's like a fire waiting to happen. :\

 

[ncampos92562]

You guys should have seen behind the radio and under the dash when I first got the car. Random wires going everywhere, most of which weren't hooked up to anything.

 

[Tyeler18]

Sounds like you either have gotten a bad new battery (won't maintain a charge) OR more likely have a large battery drain or short.

Testing battery: http://www.dsmtuners.com/forums/newbie-forum/258035-car-died-freeway-electrical-problems.html

Testing for drain/short: http://www.dsmtuners.com/forums/art...-partial-short-battery-drain.html#post1496998

This second link will help you diagnose your problem now that you've found out it isn't the battery.

 

[ncampos92562]

So following that, i need to rig up a normal light to sit between the - and + of the battery with the negative disconnected and start pulling fuses and or main current wires to devices?

 

[luv2rallye]

So following that, i need to rig up a normal light to sit between the - and + of the battery with the negative disconnected and start pulling fuses and or main current wires to devices?

No. You disconnect the battery terminal from the negative battery post. Then connect one side of a 12v incandesent light bulb or a 12v tester light (do not use an LED) to the negative battery post (so that is the ONLY thing connected to the post - no other wires). Then connect the other side of the light to the battery terminal that you just took off. This puts the light in series with the battery negative cable so if there is a power draw it will go on. Do not start the car like this. Also do not turn on anything (like opening a door so the floor light goes on, etc) as this will make the light turn on dimly and be misleading. If you must keep a door open disconnect the door open switch.

 

[ncampos92562]

Ok got it. Thanks

MERGE:
So, I was going through the fuse boxes, got to the second to last one and there it was. Pulled the fuse to my wideband and the light went out/very very dim. Is it supposed to go completely off or is barely lit good enough?

My wideband is hooked into the defogger fuse in the inside fuse box(temporarily, was waiting to rewire when I could pull the sensor to reset it). So I'm gonna relocate it tomorrow to something that won't cause a drain.

 

[luv2rallye]

Very very dim should be good enough although I'm surprised it didn't go completely out. Perhaps you have some aftermarket things installed that draw some power all the time like an alarm, turbo timer, power amp with large capacitor? Normally the only stock things that draw current with everything off are the ECU and radio memories and they only draw 50mA which I didn't think would be enough to light a bulb. But I suppose if you're using a small enough bulb it might (a headlight bulb wouldn't though).

 

[ncampos92562]

I used an old step/kick panel light I had laying around. And I do have an aftermarket alarm and an amp so it is probably one of those barely pulling power.

Thanks for all the help guys.