AutoBanter

AutoBanter (http://www.autobanter.com/index.php)
-   Audi (http://www.autobanter.com/forumdisplay.php?f=20)
-   -   Another Electrical Puzzle (http://www.autobanter.com/showthread.php?t=1280)

Wayne Crannell October 10th 04 04:04 AM

Another Electrical Puzzle
 
Here's one for the experts...

2001 Audi A6, 50000 miles.

This has been a fairly trouble free car except for front end woes fixed
under warranty and one electrical gremlin that occasionally blows fuses
to the rear power outlet (lighter).

Anyway, my wife drove it all day in the rain today, starting and
stopping at various places with no apparent troubles. Tonight, she
stopped for 20 minutes, and when she came back to it to start it, all
she got was clicking. She tells me the interior lights were fairly dim.
OK...so after she panicked a bit on the phone, she called back and said
that the interior lights got bright and the car started. The only
remaining symptom was that the radio is in "safe mode" as though the
battery had been disconnected.

So....it sounds like a dying battery that couldn't turn over the
starter....except why would there be low juice at first and then enough
to start it 10 minutes later? It wouldn't be a loose connection, because
there should have been no power at all. I'd suspect the alternator, but
then the battery should have just died and stayed dead. Could it be the
starter itself -- can the starter gears "jam"? (for lack of a better
term) Moisture somewhere? Or just the usual 2001 A6 electrical gremlins?

You can certainly see that figuring this out could run into serious
money as the mechanic spends hours and hours looking for something that
is no longer there -- until the next time, that is.

Maybe time for new battery, at least?

--
Wayne Crannell
Xxxxxxx, TX

daytripper October 10th 04 04:26 AM

On Sun, 10 Oct 2004 03:04:16 GMT, Wayne Crannell > wrote:

>Here's one for the experts...
>
>2001 Audi A6, 50000 miles.
>
>This has been a fairly trouble free car except for front end woes fixed
>under warranty and one electrical gremlin that occasionally blows fuses
>to the rear power outlet (lighter).
>
>Anyway, my wife drove it all day in the rain today, starting and
>stopping at various places with no apparent troubles. Tonight, she
>stopped for 20 minutes, and when she came back to it to start it, all
>she got was clicking. She tells me the interior lights were fairly dim.
>OK...so after she panicked a bit on the phone, she called back and said
>that the interior lights got bright and the car started. The only
>remaining symptom was that the radio is in "safe mode" as though the
>battery had been disconnected.
>
>So....it sounds like a dying battery that couldn't turn over the
>starter....except why would there be low juice at first and then enough
>to start it 10 minutes later? It wouldn't be a loose connection, because
>there should have been no power at all. I'd suspect the alternator, but
>then the battery should have just died and stayed dead. Could it be the
>starter itself -- can the starter gears "jam"? (for lack of a better
>term) Moisture somewhere? Or just the usual 2001 A6 electrical gremlins?
>
>You can certainly see that figuring this out could run into serious
>money as the mechanic spends hours and hours looking for something that
>is no longer there -- until the next time, that is.
>
>Maybe time for new battery, at least?


How old is the battery? If it's original, I'd consider replacing it and see if
the gremlin is gone for good.

Otherwise, if we presume the battery is ok....if the alternator belt was
slipping in the wet - or the alternator is simply on its way to Heaven - and
your SO had a healthy electrical load on the battery (headlights, heater or
AC, etc) it's conceivable she flattened the battery. Removing the load would
allow the battery to build up a surface charge which would give the appearance
of health - for a very short time, anyway, enough to brighten the lights and
perhaps to start the engine up.

Doubtful all those problems were caused by a fritzed starter motor (and I've
never heard of one locking up - the typical failure modes for starters are
open windings and shot bendix gear).

I'd still vote for the battery if it's original. My original battery lasted
for four years less three months, and afaik it was a four year battery (it
might have lasted longer had it not been flattened by a rear passenger reading
lamp inadvertantly left on for a couple of days :-(

/daytripper
'00 s4 6spd

Stephen Clark October 10th 04 05:50 AM

I second trip's nomination. Take out the battery and have it load tested at
an auto parts store. It could have a bad cell that can make the appearance
of an intermittent failure.

Same thing happened on my wife's Lexus with a less than two year old
battery.

Dimmed lights indicate low voltage, not a starter problem.

If it's old, even if it tests good, replace it anyway.

Same symptoms can be caused by corroded battery connections. Clean with
baking soda and a wire brush when you replace the battery.

Good luck!

--
Stephen Clark
89 Audi 100
99 Lexus RX300
Houston, Texas USA

See my Audi in the Registry at www.audiworld.com!




Mark October 10th 04 08:54 AM

Trim
> Doubtful all those problems were caused by a fritzed starter motor (and
> I've
> never heard of one locking up - the typical failure modes for starters are
> open windings and shot bendix gear).
>

Trim
> /daytripper
> '00 s4 6spd


I've known pre-engaged starters not fire once in due to a faulty winding -
solved by hitting it with a hammer! And the old bendix type not unscrewing
themselves once started and burning out the starter motor.

Other than that I would agree it sounds more like a battery problem.

I've got a 2002 A6, which had its alternator changed when one of the warning
lights came on (Traction control I think) - and then again about a day later
with the same problem. Other than that I've had no other electrical problems
in 55,000miles. Hopefully my new one will also be as trouble free.

Mark



Wayne Crannell October 10th 04 09:47 PM

In article >,
"Stephen Clark" > wrote:

> I second trip's nomination. Take out the battery and have it load tested at
> an auto parts store. It could have a bad cell that can make the appearance
> of an intermittent failure.
>
> Same thing happened on my wife's Lexus with a less than two year old
> battery.
>
> Dimmed lights indicate low voltage, not a starter problem.
>
> If it's old, even if it tests good, replace it anyway.
>
> Same symptoms can be caused by corroded battery connections. Clean with
> baking soda and a wire brush when you replace the battery.
>
> Good luck!


18 months old. Shows no problems after I messed around today. Drove the
car with absolutely no issues today.

I guess we'll have to get stranded to find out what's wrong!

--
Wayne Crannell
Xxxxxxx, TX

daytripper October 11th 04 04:51 AM

On Sun, 10 Oct 2004 20:47:48 GMT, Wayne Crannell > wrote:

>In article >,
> "Stephen Clark" > wrote:
>
>> I second trip's nomination. Take out the battery and have it load tested at
>> an auto parts store. It could have a bad cell that can make the appearance
>> of an intermittent failure.
>>
>> Same thing happened on my wife's Lexus with a less than two year old
>> battery.
>>
>> Dimmed lights indicate low voltage, not a starter problem.
>>
>> If it's old, even if it tests good, replace it anyway.
>>
>> Same symptoms can be caused by corroded battery connections. Clean with
>> baking soda and a wire brush when you replace the battery.
>>
>> Good luck!

>
>18 months old. Shows no problems after I messed around today. Drove the
>car with absolutely no issues today.
>
>I guess we'll have to get stranded to find out what's wrong!


Ah - 18 months old? In that case I'd be looking for a poor battery connection,
either the big fat cables at the battery terminals, or a grounding cable
working its way loose. Driving in the wet could aggravate a poor connection
and provide similar symptoms to what your SO experienced...

/daytripper
'00 s4 6spd

Michelle P October 12th 04 03:05 AM

Wayne,
Look for a faulty or dying Fuse. They do age and wear out with use.
Michelle

Wayne Crannell wrote:

>Here's one for the experts...
>
>2001 Audi A6, 50000 miles.
>
>This has been a fairly trouble free car except for front end woes fixed
>under warranty and one electrical gremlin that occasionally blows fuses
>to the rear power outlet (lighter).
>
>Anyway, my wife drove it all day in the rain today, starting and
>stopping at various places with no apparent troubles. Tonight, she
>stopped for 20 minutes, and when she came back to it to start it, all
>she got was clicking. She tells me the interior lights were fairly dim.
>OK...so after she panicked a bit on the phone, she called back and said
>that the interior lights got bright and the car started. The only
>remaining symptom was that the radio is in "safe mode" as though the
>battery had been disconnected.
>
>So....it sounds like a dying battery that couldn't turn over the
>starter....except why would there be low juice at first and then enough
>to start it 10 minutes later? It wouldn't be a loose connection, because
>there should have been no power at all. I'd suspect the alternator, but
>then the battery should have just died and stayed dead. Could it be the
>starter itself -- can the starter gears "jam"? (for lack of a better
>term) Moisture somewhere? Or just the usual 2001 A6 electrical gremlins?
>
>You can certainly see that figuring this out could run into serious
>money as the mechanic spends hours and hours looking for something that
>is no longer there -- until the next time, that is.
>
>Maybe time for new battery, at least?
>
>
>


--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity


Romy October 12th 04 06:15 PM


"Michelle P" > wrote in message
k.net...
> Wayne,
> Look for a faulty or dying Fuse. They do age and wear out with use.
> Michelle
>

---Snip---


Fuses do not age and wear out with use. Rubber ages, brake pads wear out,
but fuses last almost forever if not murdered. The problem is most likely a
bad (intermittant - high resistance) connection in the power circuit.




All times are GMT +1. The time now is 07:09 PM.

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
AutoBanter.com