Electrical gremlins again (crazy needle syndrome)

[Tony Hoffman]

The diodes in the alternator itself are what convert Ac to DC,
essentially just cutting of the tops (positive voltage) and then
sending that to the voltage regulator.

Tony

On Sat, Jun 5, 2010 at 1:17 PM, Radek <radek at istar.ca> wrote:
> I swapped the voltage regulator for another used one - no change.  Is voltage regulator the only device that converts AC to DC, or are there other electronic devices on the alternator that could have failed?
>
> I cleaned battery teminals and all connections I could find.  Small Audis have no splice, battery is in the engine compartment.
>
> Any ideas?  Do I need a new alternator or a new volt gauge?
>
> Radek.