Strange voltmeter readings

[Tex Terry, II]

Vic - Do you have access to a volt meter?  While the engine is running,
check the volts at the battery.  If the meter shows 12.5 or more volts,
then I would say that the alternator is still putting out to the battery,
and that is why you are still able to restart, and the load of the lights
does not affect anything.  I would then see if you can get hold of a known
good gauge and temporarily replace in place of yours.  If you can access
the connection to the gauge, disconnect at that spot and connect the meter
and take a reading (one meter lead to the gauge connection and one to a
good ground).  If you don't have access to a meter, most auto parts stores
now offer a free check of the alternator, while it is still in the car. 
Drive to one and have them check it to determine if the alternator is okay.
 It might be the regulator only, or the alternator or just the gauge.  Tex.
> 
> Message: 1
> From: "Vic Norman" <vicn at icarz.com>
> To: <quattro at audifans.com>
> Subject: Strange voltmeter readings
> Date: Fri, 18 May 2001 10:59:57 -0400
> 
> 
> The voltmeter on my 1991 Audi 100 normally registers a little over 12
volts
> when the engine is running. On occasion, however, the reading will drop
> considerably. Lately, it's been all the way down at 8 volts at times.
> Turning headlights etc on or off doesn't change the reading. Nor does the
> low reading affect the car, it starts and runs fine,  so I'm sure the
> battery isn't really down to 8 volts.
> Anyone have any suggestions as to whether I should be worried or just
ignore
> the damn thing?
> 
> Thanks.
>