New Battery dead after one night

[pensacola mike]

Hello, I need some guidance. I just purchased a new battery for my 87 Carrera. The reason I needed a new battery is because it would not hold a charge and so I purchased a new one from battery source store and after driving the car to and from work it will not start this morning. I checked the battery with a volt meter and was reading 11.2v. could it be that I need a new alternator? or could there be something else drawing amps?

Mike.

[Dave Colangelo]

How did you confirm the original battery was not holding charge? It sounds like your alternator is going not your battery. You could put an ammeter inline from the alternator and see if its driving any current to confirm it works. How old was the first battery? What do you mean by not hold a charge? Would you charge it from the wall and then after starting the car it would die? Would the car run for a few weeks then not start?

Regards
Dave

[pensacola mike]

Dave, thank you for your response. I charged the battery with a battery charger and the car would start and run fine the next morning the battery had gone from 13.3v to 9.0v and the car would not turn over so I thought after the second charge the battery was dead and it was 3 1/2 years old.

[emac]

Mike had this happen to me. Check that the glove box light switch is not turned on
Ernie

[JJ 911SC]

Originally Posted by emac

Mike had this happen to me. Check that the glove box light switch is not turned on
Ernie

If its not that, put an Amp meter in series with the battery ground and see if there is a current draw (more then likely). If so, remove the fuse one a the time to find the culprit.

[darrin]

mike -- agree with jj911sc that you have a drain problem and need to identify the culprit.

Do your interior lights come on when you open your driver's side door? A failed door pin switch can lead to a parasitic drain, as the power window circuit remains active after you turn off the motor (to let you roll back up windows) and is deactivated when you open your door -- so, if your door switch doesn't work, the power window circuit will remain active indefinitely, causing a drain on your battery.

[pensacola mike]

These are all great starting points. Thank you all for you wisdom and experience. Just feeling a bit frustrated being at work and not able to figure out exactly what the problem might be. I do have a faulty door light switch I have to wiggle it to turn the lights on and I did mess with the glove box light the other day. But I have to recharge my new battery and try to find the culprit.

[Dave Colangelo]

Sounds like a drain, along with all the things mentioned if you cant find the source in a place like a light or bad switch take a look got shorts and things like that.

Regards
Dave

[aoncurly]

Originally Posted by emac

Mike had this happen to me. Check that the glove box light switch is not turned on
Ernie

Also, check your frunk light. I had always left my frunk unlatched because I cover my car and I put the cover in there. With the frunk hood down but not latched, the light was on and I could not tell that it was on. I still do the same now with the hood, but I disconnected the light and wrapped the spade with electrical tape.

[pors1968]

Simple check door swicth check if your electric window still working whith door close.Key off swicth door close.

[Bob Kontak]

Originally Posted by aoncurly

..............but I .......... wrapped the spade with electrical tape.

Glad you said spade. If you buy one of those spade dis-connectors at the car parts store it will buy you some time and they are not that hard to install on the neg terminal.

You can drive it back and forth to work if your battery reads above 13.5 when you are running (hopefully charging). Just cut the flow when you get to work/home.

Do look on youtube for how to use a multi meter. It explains testing in series if you don't know as you need to do the test jj911SC suggests. I did it for the first time a few years back checking my fuel pump amp draw. Easy once you know how.

[Porchdog]

My 81 had a Clifford (aftermarket) alarm, and would discharge the battery (Optima Yellow) in a couple of days.

I comprehensively removed the alarm and repaired the installer's splices. When I removed the solenoid on the trunk latch it was very hot to the touch - I assume that it failed somehow and was constantly drawing current.

No more problems with dead batteries.

[pensacola mike]

Okay, I charged the battery for three hours and the car starts up no problem. I disconnected the frunk light, door light switches and made sure the glove box light was off. I'm not sure if there is a problem or a benefit with owning a later model 911 (87) but when I take the keys out of the ignition and open the doors I can still raise and lower the windows. Is this supposed to happen or like Darrin mentioned it is supposed to turn off?

Today, I have the car parked and the negative ground cable detached from the battery and will see if what I have done solves the drain.

[Smoove1010]

I have an '87 Cab and my power windows also work when the key is off and removed from the ignition switch. I don't have the power leakage like you do though.

Check the light under the engine hood as well. I had a VW Jetta years ago with a battery that went dead on me sporadically - turned out that the trunk light wasn't turning off when the lid was closed.

The "dirty" way to find a leaky circuit is to remove fuses one at a time when the car is off. Whichever ones give you a little spark may be suspect.

Good luck,
Gk

[wwest]

No one should EVER advise putting an amp meter in series with a car battery absent being certain the ADVISED has a full understanding of the situation electrically.

[ischmitz]

The other way to quickly check for drain is to fully charge the battery then disconnect or disable the trunk light and disconnect the negative at the battery. Next touch the negative pole of the battery with the negative cable gently and watch for an ever so small spark. If you see the tiny sparks when touching the pole it confirms you have a drain somewhere.

Popular items as others mentioned are the glove box light and aftermarket alarms. For a real test get a DVM meter in the 10 Ampere or 20 Ampere range and measure the drain. If it is low enough you can use the smaller range to better quantify it. Remember that both ranges are fused and a quick mistake blows the internal fuse in the Multimeter and then it won't register. So there is some basic knowledge required to use a meter in Ampere setting. For starters the meter has to be in-line to the circuit (contrary to a voltage measurements that is parallel to the source)

Once you have confirmed a drain start removing fuses one at a time to isolate where the drain is located. If that fails and all "usual suspects" are eliminated you could have a bad diode in the alternator. Remember the alternator is connected to the battery at all times. A diode can become partially damaged to where its leakage current goes up drastically.

Regards,
Ingo

[JJ 911SC]

Originally Posted by wwest

No one should EVER advise putting an amp meter in series with a car battery absent being certain the ADVISED has a full understanding of the situation electrically.

Yes and no.

If you know what an Amp meter is, you don't need to read the 21 pages of warning of what not to do, depending where you live.

The worse it could happen is you would blow the internal fuse, unless you are having a piss while holding both wires.

[JJ 911SC]

Originally Posted by dthzhen

Dave, thank you for your response.

Say good night spammer...

[billybek]

When checking amps while the car is off, loosen the negative post.
Place your meter (a decent meter) in the inline (through the meter) DC amps mode.
clip one lead to the negative battery clamp and make contact with the post with the other before you remove the clamp from the negative battery post. (did that make sense?)

What you don't want to do is disconnect the clamp from the post then place the meter across it.
The initial amount of amperage may be quite high and take the fuse out of the meter.

I had used this technique to sneak up on an intermittent pull down on my wife's car. Turned out it was the remote starter/alarm package.

[pensacola mike]

I figured it out! But I could not have done it without the help of this community. So, it looks like I will be reading up the central locking system a bit more. Once I unplugged the central lock system under the frunk the battery drain has stopped and no more spark on the negative terminal when the ground wire is re-attached. what a relief. thank you all.