Chrysler neon flat battery

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Gingertim - 14 May 2008 17:22 GMT

Hi, i have a neon that has a battery that goes flat after 36 hours.
The battery has been tested and appears to be fine so does the
alternater. I’ve put a multi meter on the battery terminals and it has
a drain of 0.032 amps. If i remove fuse number 4 from the dash it
drops to 0.002 amps and the same happens if i remove fuse 13 from the
under bonnet. Both these fuses appear to effect the interior lights.
the fuse 13 also does the radio. I’ve checked that the lights are not
being left on and have even disconnected them but does not effect the
amp reading, i’ve done the same with the radio too. I’ve try’d to
locate the auto dimmer relay for the lights but can’t find it? Has
anyone got any idea where it is or any other ideas what the problem
could be? Thanks for looking, i look forward to hearing from you.

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Joe Pfeiffer - 14 May 2008 20:49 GMT

> Hi, i have a neon that has a battery that goes flat after 36 hours.
> The battery has been tested and appears to be fine so does the
> alternater. Ive put a multi meter on the battery terminals and it has
> a drain of 0.032 amps.

Something is wrong. If you're really only drawing 32mA, a 700
amp/hour battery should last over 21,000 hours. Something is wrong
either with whoever tested your battery, or you're losing a lot of
additional current somewhere other than where you're measuring it.

You mention it's been tested, and that you've used an ammeter to
measure the current draw. So... just want to be sure that you didn't
put a voltmeter on the battery as the test: it has to be tested under
load. If you didn't take it to your favorite auto parts store and
have them put it on a tester, you need to.

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Bryan - 15 May 2008 04:32 GMT

> > Hi, i have a neon that has a battery that goes flat after 36 hours.
> > The battery has been tested and appears to be fine so does the
[quoted text clipped - 11 lines]
> load. If you didn't take it to your favorite auto parts store and
> have them put it on a tester, you need to.

Same with the alternator -- a 'good' output voltage is meaningless without a
load.
Assuming it tests good under load, there should be some Field current... a
few amperes at full load. No field current = no output. If no Field
current, look 'upstream' from the Field connection. A wiring diagram will
help you troubleshoot it if that's the problem.

Bryan

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Ron Seiden - 15 May 2008 02:42 GMT

Check the battery cable connections...

> Hi, i have a neon that has a battery that goes flat after 36 hours.
> The battery has been tested and appears to be fine so does the
[quoted text clipped - 8 lines]
> anyone got any idea where it is or any other ideas what the problem
> could be? Thanks for looking, i look forward to hearing from you.

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Ted Mittelstaedt - 15 May 2008 05:45 GMT

1) Park car. measure voltage across battery. Start car. Measure
voltage across battery terminals again. It should be higher by at least
a volt, better 2 volts. stop car.

2) disconnect negative battery cable from battery for 36 hours

3) Reconnect negative battery cable.

4) Start car. Does it start? If so, battery is fine. If not, battery has
a shorted cell or high internal leakage current. These may not always
show on a battery tester.

If the battery will not hold a charge and is still under warranty, and you
are unable to convince the retailer of the battery that the battery is dead,
then go to a wrecker and buy a used battery. Park car, turn on headlights
and leave on for 36 hours until the existing battery is stone dead. Replace
existing battery with used battery. Leave dead battery sitting for 1 month
and drive on used battery. Take dead battery in for testing. There will
be nothing they can do that will make it fool the tester into believing that
the battery is good. You will get your warranty battery. Take out the
used battery and store it in the garage and charge it every couple months
until you need it again.

I had to do that to a Sears DieHard once, after that I swore that I'd
never buy a battery from an auto parts store or service center. Now I
get them from the mass retailers like a sporting goods store or walmart
or a tire store. Those guys do not have "know enough to be dangerous
but don't know enough to know what they are doing" people who work
for them and who will argue with you over a battery warranty. And
the batteries I get from the mass marketers have far fresher date codes,
and last many years longer, and are cheaper.

Ted

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Mike Y - 15 May 2008 14:31 GMT

> 1) Park car. measure voltage across battery. Start car. Measure
> voltage across battery terminals again. It should be higher by at least
[quoted text clipped - 29 lines]
>
> Ted

I agree with Ted but would like to point out that 2v change at running to
not running might be about it. Years ago there were huge changes because
alternators had two charge rates. High and Low. In the 60's, Shell
had a 'Tips for Drivers' handbook they gave out free (when's the last
time oil companies gave out free stuff?) that had tip to charge your
battery faster after a jumpstart, turn on the lights. That was because
on most vehicles, it would force the regulator to high charge rate.

Nowadays, charging is computer controlled with a variable field, and
the alternator 'tracks' the battery to just a bit above what it should be
at and compensates for electrical load. That's why batteries last an
incredibly long time even with the tremendous demands modern cars
put on them.

But the concept should still be you see the battery voltage HIGHER
when the vehicle is operating.

Also, check your voltage under different conditions. Get a cigarette
lighter plug and make an adapter to your meter, and see what is
happening when the vehicle is being driven, not idling in the driveway.
I had an old Mustang once that would charge at idle, but not on the
highway. I took a 6 hour trip, and it ran the battery down. Was
as simple a solution as tightening the belt.

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Bob AZ - 15 May 2008 05:50 GMT

I’ve try’d to

> locate the auto dimmer relay for the lights but can’t find it? Has
> anyone got any idea where it is or any other ideas what the problem
> could be? Thanks for looking, i look forward to hearing from you.

Gingertrim

Two possibilities. Your battery is not really being properly charged
and/or it has a bad cell.

So when you think it is properly charged monitor the battery voltage
and turn on the headlights. If you have a bad cell it will promptly
drop at least 2 volts. Maybe more.

Also check the charging system for a voltage drop between the
alternator output and the battery. Usually less than .3 volts. I
imagine the spec is .5 volts but all that I have tested are less than .
3 volts.

Also check for clean tight battery and battery cable connections.

Hope this helps.
Bob AZ

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