Strange battery / electrical problem
 

Last week, I go out to use my car and the battery is completely dead. So
dead even the car clock isn't functioning. I see from my receipts that
the battery is 7½ years old, so I figure I'll just replace it, which I
do. I get an Exide with 700 CCA (basically same model as I bought 7+
years ago; no problems). I drove the car for 10 min., parked it, and
left it for a week. (BTW, electric windows, fan, etc. worked fine.) I
come back this morning and it is completely dead--not even the clock was
working (the same deadness that caused me to replace the battery).

At the garage, the mechanic tells me the alternator is putting out <13,
that the minimum is 13.5, and that I need a new alternator. As far as
the drain, he has no idea.

Now, the only thing I had happen to the first dead battery was a fuse
issue. The fuse controlling the interior lights went out. I mistakenly
popped in a 20 amp when it called for a 15. When the lights didn't work,
I discovered my mistake, put in the proper fuse, and everything was OK.
The car worked fine for a week, and then the battery problem.

So, any ideas as to what is draining my battery?
This car is an '84 Audi 5000 wagon. The battery is in the back seat.

I know it's old but otherwise it's in great shape. I'd like to keep it
around for a while longer.
Appreciate any and all help.
Thanks,
Bill

Re: Strange battery / electrical problem
 

My '87 5000S had a low charging voltage problem. I traced it back to a
poor connection at the field wire connection at the alternator. A
small amount of resistance here can affect the charging current. If
the alternator has removable brushes (my old BMW did) then this would
cheaper and easier than replacing the whole thing.

As for the power drain, I suggest you disconnect the battery, charge
it, then insert a multi meter (set on Amps) between the positive post
of the battery and the detached positive cable. Read the drain --
should be no more than ~20mA. If it's more (greater than 10A may pop
the fuse in the multi meter), then start pulling fuses one-by-one
noting any change in the drain current. You may also have to pull
relays. (Note that if the drain is large, then letting it drain for a
while should warm up the fuse and/or relay, perhapsallowing you to
find it with out removal.) Hopefully you'll eventually find a circuit
with a minor short; if you do, then start disconneting devicee on that
circuit, such as pulling bulbs, disconnect the big plug on the back of
the radio, the master window switch (driver's door), etc. (the fuse
panel cover should list everything on a given circuit).

Good luck!
Jaz

PS, a buddy of mine thought he had a bad battery on his camper so he
replaced it... then he decided he must have a power drain... until I
pointed out that he had been leaving it on Accessory. Days later he
decided that he indeed had a drain, and it was probably through a bad
alternator diode, so he replaced the alternator... until I pointed out
that the left-most key position was Accy, not Off. The upside is that
he now has both a new battery and anternator. LOL.

On Mon, 15 Sep 2003 13:35:56 -0400, BG <bgreene@nac.net> wrote:

>
>Last week, I go out to use my car and the battery is completely dead. So
>dead even the car clock isn't functioning. I see from my receipts that
>the battery is 7½ years old, so I figure I'll just replace it, which I
>do. I get an Exide with 700 CCA (basically same model as I bought 7+
>years ago; no problems). I drove the car for 10 min., parked it, and
>left it for a week. (BTW, electric windows, fan, etc. worked fine.) I
>come back this morning and it is completely dead--not even the clock was
>working (the same deadness that caused me to replace the battery).
>
>At the garage, the mechanic tells me the alternator is putting out <13,
>that the minimum is 13.5, and that I need a new alternator. As far as
>the drain, he has no idea.
>
>Now, the only thing I had happen to the first dead battery was a fuse
>issue. The fuse controlling the interior lights went out. I mistakenly
>popped in a 20 amp when it called for a 15. When the lights didn't work,
>I discovered my mistake, put in the proper fuse, and everything was OK.
>The car worked fine for a week, and then the battery problem.
>
>So, any ideas as to what is draining my battery?
>This car is an '84 Audi 5000 wagon. The battery is in the back seat.
>
>I know it's old but otherwise it's in great shape. I'd like to keep it
>around for a while longer.
>Appreciate any and all help.
>Thanks,
>Bill
>

Re: Strange battery / electrical problem
 

The test procedure should be followed. If I were to guess what you find
it would be broken and frayed wires in the drivers door hinge area. The
rubber accordion contains a lot of wires for multiple accessories and
flexing breaks the wires. Some are hot all the time and if one of those
shorts with a ground ...

Tony
'91 100Q 5spd
BTDT

Jaz wrote:
>
> My '87 5000S had a low charging voltage problem. I traced it back to a
> poor connection at the field wire connection at the alternator. A
> small amount of resistance here can affect the charging current. If
> the alternator has removable brushes (my old BMW did) then this would
> cheaper and easier than replacing the whole thing.
>
> As for the power drain, I suggest you disconnect the battery, charge
> it, then insert a multi meter (set on Amps) between the positive post
> of the battery and the detached positive cable. Read the drain --
> should be no more than ~20mA. If it's more (greater than 10A may pop
> the fuse in the multi meter), then start pulling fuses one-by-one
> noting any change in the drain current. You may also have to pull
> relays. (Note that if the drain is large, then letting it drain for a
> while should warm up the fuse and/or relay, perhapsallowing you to
> find it with out removal.) Hopefully you'll eventually find a circuit
> with a minor short; if you do, then start disconneting devicee on that
> circuit, such as pulling bulbs, disconnect the big plug on the back of
> the radio, the master window switch (driver's door), etc. (the fuse
> panel cover should list everything on a given circuit).
>
> Good luck!
> Jaz
>
> PS, a buddy of mine thought he had a bad battery on his camper so he
> replaced it... then he decided he must have a power drain... until I
> pointed out that he had been leaving it on Accessory. Days later he
> decided that he indeed had a drain, and it was probably through a bad
> alternator diode, so he replaced the alternator... until I pointed out
> that the left-most key position was Accy, not Off. The upside is that
> he now has both a new battery and anternator. LOL.
>
> On Mon, 15 Sep 2003 13:35:56 -0400, BG <bgreene@nac.net> wrote:
>
>
>>Last week, I go out to use my car and the battery is completely dead. So
>>dead even the car clock isn't functioning. I see from my receipts that
>>the battery is 7½ years old, so I figure I'll just replace it, which I
>>do. I get an Exide with 700 CCA (basically same model as I bought 7+
>>years ago; no problems). I drove the car for 10 min., parked it, and
>>left it for a week. (BTW, electric windows, fan, etc. worked fine.) I
>>come back this morning and it is completely dead--not even the clock was
>>working (the same deadness that caused me to replace the battery).
>>
>>At the garage, the mechanic tells me the alternator is putting out <13,
>>that the minimum is 13.5, and that I need a new alternator. As far as
>>the drain, he has no idea.
>>
>>Now, the only thing I had happen to the first dead battery was a fuse
>>issue. The fuse controlling the interior lights went out. I mistakenly
>>popped in a 20 amp when it called for a 15. When the lights didn't work,
>>I discovered my mistake, put in the proper fuse, and everything was OK.
>>The car worked fine for a week, and then the battery problem.
>>
>>So, any ideas as to what is draining my battery?
>>This car is an '84 Audi 5000 wagon. The battery is in the back seat.
>>
>>I know it's old but otherwise it's in great shape. I'd like to keep it
>>around for a while longer.
>>Appreciate any and all help.
>>Thanks,
>>Bill
>>
>
>

Re: Strange battery / electrical problem
 

On Mon, 15 Sep 2003 22:18:45 -0500, TonyJ <tonyjNOSPAM@NOSPAMvisi.com>
wrote:

>The test procedure should be followed. If I were to guess what you find
>it would be broken and frayed wires in the drivers door hinge area. The
>rubber accordion contains a lot of wires for multiple accessories and
>flexing breaks the wires. Some are hot all the time and if one of those
>shorts with a ground ...
>
>Tony


Oh yeah, I had that!

Re: Strange battery / electrical problem
 

Well, Tony, you nailed it!
Thanks for the excellent advice.
-bill



BG wrote:

> Last week, I go out to use my car and the battery is completely dead. So
> dead even the car clock isn't functioning. I see from my receipts that
> the battery is 7½ years old, so I figure I'll just replace it, which I
> do. I get an Exide with 700 CCA (basically same model as I bought 7+
> years ago; no problems). I drove the car for 10 min., parked it, and
> left it for a week. (BTW, electric windows, fan, etc. worked fine.) I
> come back this morning and it is completely dead--not even the clock was
> working (the same deadness that caused me to replace the battery).
>
> At the garage, the mechanic tells me the alternator is putting out <13,
> that the minimum is 13.5, and that I need a new alternator. As far as
> the drain, he has no idea.
>
> Now, the only thing I had happen to the first dead battery was a fuse
> issue. The fuse controlling the interior lights went out. I mistakenly
> popped in a 20 amp when it called for a 15. When the lights didn't work,
> I discovered my mistake, put in the proper fuse, and everything was OK.
> The car worked fine for a week, and then the battery problem.
>
> So, any ideas as to what is draining my battery?
> This car is an '84 Audi 5000 wagon. The battery is in the back seat.
>
> I know it's old but otherwise it's in great shape. I'd like to keep it
> around for a while longer.
> Appreciate any and all help.
> Thanks,
> Bill