3 liter V6 drains 10 amps at rest, no smoke.

My '95 leBaron with a 3.0 liter engine has a problem new to me.

The charger shows 12 amps going into the car, even when the battery is
disconnected, the ignition is off, the key is out, but nothing is
smoking!

Where is all the current going?

When the charger is connected, and the battery isn't, the door locks
work slowly and when I turn it on, the radio lights up but barely.

The car was running fine when I parked it last.

To start from the beginning:
The battery was dead in the morning, after not using the car
yesterday. I hooked up the charger and it was putting more than 12
amps into the car/battery, but the battery car got no closer to
starting the car. Totally dead. (I don't see how the battery could be
the problem but for the record, I disconnected the + cable to the
starter, and the battery showed 5 volts but would barely accept
anything from the charger. But that increased to 6 amps and the
battery was over 12.2 in a few minutes when I had to stop.)

The resistance of the whole car, not including the battery, is 40
ohms. Darn, I forgot to measure it in the other direction.)

What should I do next?

P.S. I have the strange feeling that I need to hit the starter motor
with a hammer.

Thanks for any help you can give.

 

Here are sxome things to try:

Disconnect one or more circuits to isolate the problem (pull fuses or
unplug things or whatever - do you have the vehicle schematics?) - IOW -
disconnect everything from the main bus - you should have almost zero
current draw from your charger with that. Then connect a circuit at a
time until you get the high current draw again. That will tell you which
circuit has the short.

It sounds like the battery is fried due to being severely drained
possibly as a result of the original problem (a short). So now you have
two problems - a short and a boat anchor battery.

What is the current rating of the charger you are using?

When you have the battery disconnected and you hook up the charger to
the car (not the battery), what voltage do you measure?

The charger is going to put out its programed limit of current even if
there's a dead short to ground in the car's main power bus - and that
could very well be what you are seeing.

The 40 ohms you are reading may not mean anything because the meter
doesn't try to force a very high voltage onto the wires to make that
reading. It may be a non-resistive short. You may have something
shorting out above, say 3 volts. I think the voltage reading with your
charger hooked up without the battery will tell part of the story.

SUMMARY: (1) Isolate the circuits to see which one is shorted. (2)
Measure the voltage at the charger output when it is connected to the
bus with the battery disconnected.

 

Also - a test light (get it at you local auto parts store) may help in
the isolation of the circuits to find out which one is shorted. With
main fuses pulled, put voltage to the bus, then bridge the fuse holders
one at a time to see which one lights the light - thats the circuit with
the short.

 

It isn't a good idea to connect a charger to the car with no battery
in place. Electronics like clean even power. When you hook the
battery charger directly to the car with no battery you loose the
inherent filtering capacity of the battery and battery chargers put
out particularly nasty power because there is normally no need to
filter their output.

Basically having the car on a charger with no battery will cause the
electronics to go nucking futs and anything is likely to be happening.
A battery that was at 5V did not charge back up in a couple of
minutes. I would recommend that you fully charge the battery and have
it load tested then put it back in the car. Give the system a little
time for the computers to do what they need to do and see what the
power draw is.

My hunch is that you have a battery that has croaked and once you
replace it things will return to normal. I could very well be wrong
though... make sure you test the actual current draw with the battery
in the vehicle to see what's goin on.

Steve B.

 

You are correct about the filtering that a battery provides in the
electrical system. But that still doesn't explain the 12 amps that the
vehicle is drawing from the charger. Something is presenting a
conductive path to ground for it to be pulling 12 amps with everything off.

I agree that the battery needs to be working (the one he has is probably
toast due to being totally depleted and left that way for a time), but
there is something that is pulling current - in other words, a short.

 

Internal short within the battery due to failure of one or
more cells - mechanical failure vs chemical failure.