I have a 2000 A4 2.8 quatro, battery went dead, after external recharge in-dash voltometer showing no charge and there is an intermittant buzz (guessing it is some kind of warning) from the dash. Belts are OK, likely culpret alternator or regulator? Thanks in advance.

 

What is the actual voltage with the car running?

 

zero -0-

 

in-dash gauge shows zero, warning sound is buzz -buzz buzz- in 1 second intervals, car starts fine with charged battery, happened all of a sudden, one day fine next - done.

 

There is a common earth (ground?) on the top of the engine with a bolt having a 10mm head that may be loose or corroded. If that is the case, some of the gauges and other equipment will not function correctly.

 

If your voltage is 0 your car is not running I guess you should start wasting your money by throwing parts at your car in a sad attempt to try & fix it!

 

Have you checked the cable connections at the battery and attempted to verify the voltage at the battery with an external gauge such as a multimeter to determine if the charging system is functioning?

The alternator should be sending between 13.0 to 14.5 to the battery.

 

Something is wrong with this whole story.

As M5S5 said, if the car is running the voltage is not 0. I don't know how you're taking that reading, but its unpossible.

If the voltage is 0, what's producing the buzzing noise?

It all makes me wonder if you're relying on some gauge that's dead. And frankly, I think you need to take that car to someone else to diagnose it. We're just not getting very good data here.