About a month ago, I was driving the car and had the voltage regulator go out, or so I thought.
The car is a 1970 Z with a new (bought in January) alternator.
The car had been sitting for an hour or so in a restaraunt parking lot on a weekend night spent cruising with some friends.
About five minutes after leaving the restaraunt, the lights get real bright and the aftermarket volt gauge is pegged as high as it can read. There was a whiring noise coming from under the hood that sounded like a mini turbo spolling up during acceleration. I'm stuck in major traffic and cant get off the road before the lights dim down to what seems to be normal and the noise is gone, but the volt gauge needle is now sunk to nothing. I ended up driving it home without it dieing and its started up ever since then.
I had the alternator checked out as it had been just replaced and its fine, so I replaced the external voltage regulator.
The gauge needle still does not move and the lights seem to be dimmer than they should, or maybe I just think they are. But the car runs and has not died or stalled from lack of juice. Did the gauge get fried?
Electrical systems are my weakest automotive knowledge, so any guidance on where to start looking for the problem is appreciated.

I had the same kind of problem, I turned out to be the battery post needed cleaning, and some die electric grease added to the post. Start with the simple things!!! Loose/bad connections play crazy things on your electrical system;) Your gauge appears to be fried. (check for a good ground)

Hope that helps

besides doing what was mentioned above, test your voltmeter to make sure it is fine.....if your battery has not died, it means that the alt is charging. If the charging system was bd, the GEN light would also be on......of you have one of those.

Thanks for the response guys.
The cars got some other problems; the horns havent worked since I bought the car eight years ago, the windshield wipers arent working.
I need to get a test gauge and learn how to use it.