drain on battery?

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Since the weather has gotten cold, a dead batteriy every morning on my
2000 Toyota Solara V6.

When the neg. battery cable is disconnected, an ammeter between the
cable and the post shows 0.5 to 0.8 amps!!  On the 10 amp scale.  The
doors are shut, the ignition off.    The burglar alarm is not set, but
its dash light flashes whether set or not.  That's beten true since I
got the car.  (I thought it was only supposed to flash after I armed
the alarm.)  How much current should the alrarm use?

Is this particular car subject to this problem, or does  point 5 to
point 8 sound like a particlar kind of light or device.

Any suggestions where to look?

It's a new car to me -- all my other cars were American -- and a newer
car,, and most things are powered by relays and the relays controllled
by the ECU.   Plus it's cold out.

I bought a used car with no holes punched to indicate when the battery
was bought, and assumed it was old and no good, and almost bought a
new battery without doing adequate testing.    

Thanks for any help you can give. .

Re: drain on battery?
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Some, but not that much.  And it should settle down after the battery has
been connected for a few minutes.  I suspect it doesn't settle down because
if it did your battery wouldn't be going dead.

I think it's time to start pulling fuses until the problem goes away and
then you can at least locate it down to a single fuse.

If all the fuses are pulled and the load persists, disconnect the alternator
lead next.
"C'est un Nagra. C'est suisse, et tres, tres precis."

Re: drain on battery?
On 4 Jan 2012 14:30:13 -0500, snipped-for-privacy@panix.com (Scott Dorsey) wrote:

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I guess that's what I have to do, alas.   (I had forgotten about
fuses, reverting to my first dead battery in 1964.  If that car had
fuses, they weren't all in one place, or even four places like this
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Good reminder. I don't think it will come to that.

Friday it's supposed to be warm again.  I'll just disconnect the
battery each night until then.

BTW, I'm sured to lead connectors on battery cables.  This toyota uses
steel but only at the top and bottom  1/8ths of an inch.   I don't
tlike change in general, but I coudlnt' see anything wrong with this
until today.   With lead connectors, they don't have to be tightened
for one day use.  You can just twist them on to the tapered battery
post.  I don't think that will work with this car.  Ugh.

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Re: drain on battery?
micky wrote:
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Current meter reads a number.  .5 to .8 is not a number.
That begs the question, what are you really measuring.
Does it switch between two values periodically? wander around?
The nature of the variability may have some diagnostic value.

How long did you measure it?
The ECU might take some time to reboot, diagnose itself,
etc.  That might not be affected by the ignition switch.
Same for a complex entertainment system.

You'd expect "leakage" like in an alternator diode to be constant
or at least vary monotonically with time.

If you have a 40AH battery, .5A will run it down in 80 hours.
Shouldn't kill it overnight.

I once had a battery with acid residue on the top.
Could put the voltmeter on one terminal and drag the other across the top.
Got position dependent voltage.  Cleaning off the top of the battery
removed the leakage path across the top of it.

Could have a stuck relay keeping some part of the emissions control
system stuck on.

Some aftermarket stuff has two power leads.  One goes to the battery
and the other to the ignition switch.  Not unusual to have the installer
hook it up wrong.

Once you narrow it down to the circuit by pulling fuses,  a DC current
clamp can helpful to find the culprit.  Too expensive to buy for one use,
but many auto parts stores will lend you tools.  Call around and see
if anybody has a DC current clamp they'll let you use.

Battery stores will often do a free diagnostic for you.

Re: drain on battery?

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Wander. 5 seconds.  Twice.

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Good to know.  I'll try it longer.
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I have a hydrometer to check the battery with, but it's buried in a
closet.   Maybe I'll dig it out.    Yes, the caps come off.
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Good to know. No aftermarket stuff on this car, except the Scan Guage
II that I installed.  It does load and report error codes, even when
the ignition is off, but I disconnected it and that's when I measure
the amperage again.
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Ok.  I may well do that.

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Good idea. Thanks.
Re: drain on battery?
micky wrote:
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Connect up your tester and shut the hood. Let it set without touching
anything for 30 minutes or so. See what the meter reads now.

And since you say the battery has been dead every morning you will want
to replace the battery anyway. They really don't like cycling that way.
Usually you can get away with it once or twice. BUT if it has been below
freezing when the battery goes that low it is very close to junk now.

Is the alarm a factory unit? If so then most of those don't require you
to arm them. Plus on many the security/alarm light will flash regardless
as that way thieves won't really know if it's armed or not.

Steve W.

Re: drain on battery?

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Yes. But the instructions say to, and imply it's not armed until I do.
This is 2000.  They're probably fancier now. .  

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That could well be.


Tomorrow is a little warmer and Friday is supposed to be in the low
50's.  A better day for a couple hours of testing.   I'll try to post

Re: drain on battery?
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The trunk. My wife's Solara (2001) had the same problem, the fine japanese
craftsmanship uses a bent peice of metal to hold the plunger switch in for
the trunk light.

She loaded a luggage bag or something similar, hit the switch and it fell
off, since the plunger needs to be pushed down to turn the light off, and
it's on when you open it, you don't think anything is wrong.

So take a look around in the trunk, I think the switch is near the back of
the trunk lid, been a while since I looked in there.


Re: drain on battery?
On Thu, 5 Jan 2012 14:47:24 +0000 (UTC), Bruce Esquibel

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I haven't looked yet, I haven't even stood up yet, since I read this,
but I think the swtich in my car is the lock mechanism (in the car,
not the lid). It sounds like they went to a worse design between 2000
and 2001.   I think there is a second switch too which disables the
alarm when one uses the key to unlock the trunk.   This is all based
on my recollection from September, and my Electric Wiring Diagrams
book from Toyota, sold at an absurdly high price.  50 dollars I think
it was on ebay, although I bought more than one book at the same time
on ebay and got a disount somewhere. .

But that doesn't mean mine's not broken too.   I will check this
afternoon, or maybe tonight when it's dark out.   Or I'll remove the
bulb so I can check during the day.

The light in the Lebaron trunk was over to the side and inadequate,
and I put in a better light on the turnk lid.     Thie Toyota light is
back past the lid, and only illuminates stuff in the far back.  Also
inadequate.   Now I'm hooked on those little LED flashlights (I like
the ones with 10 LEDs, so I may not add another light to this car.
(at least not until summer. :-)  )


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Re: drain on battery?
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battery effectively.


Re: drain on battery?
On Tue, 17 Jan 2012 16:57:57 -0800 (PST), Rahuuul Sharma

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Thanks.  I had to turn off the computer, and my 15 year old vesion of
agent forgets what windows,. whicn ngs, were open.   So I forgot to
come back and reply to you.

It turns out the trunk light must have been on for a while, and that's
where I got the strange readings for a while.

But that was not the big problem, which was a dying battery like I had
thought.   New battery, no problem so far.   Not sure how it compares
to the trunk light but i left one dome light on for 20 hours, car
started fine.

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