Car suddenly turned off by itself!?

Sounds like the ac clutch on the ac locked up and stoped the car.

Try this. Start the car, and then turn on the ac if you hear a screaching nose the clutch on the ac has locked and the belt is slipping on the clutch. If this happons turn off the ac ASAP

How new a car is that?

The car would shut off because the amount of "idle" fuel wasn't sufficient to keep the car running and the A/C on. The "idle" fuel is the amount of fuel delivered to the engine when you are not pressing the gas pedal.

With the A/C on full blast, the car requires more fuel. It is possible to adjust that, but I wouldn't recommend it because it would be burning extra fuel all the time.

Doesn't sound like anything is seriously wrong (potential for a fuel leak or something else causing it to burn more fuel than normal, such as a cold engine or clogged exhaust system). I wouldn't worry.

In response to a couple of the other answers:

A 1999 VW is new enough that it wouldn't have an ammeter at all, but instead a voltage gauge.

It is also new enough that it would adjust its own idle fuel with the AC on, (if the engine computer is working). If it's also running somewhat poorly, this could mean that there is something wrong with the engine computer or one of its sensors.

Did you pay any attention to the ammeter in your dashboard while you were driving with the a/c running? When the car engine died did the ammeter show a complete negative reading before you turned the ignition and a/c off? When you restarted the engine, did your ammeter jump to a complete positive reading? If your ammeter didn't show any responce one way or another, I'd say your alternator had quit working on you.

Sometimes, when a car's idle is too low, the extra power required to run the air will make the engine quit. This is probably nothing to worry about,unless it starts to do it consistently, and if so there is a possibility that the bearings on your air compressor are going bad.

For a vehicle to suddenly stop suggests that you may have a loose wire or connection in the low tension side of you ignition circuit. try doing some continuity tests. if you are not sure how to do them seek an auto electrician. if not could get a lot worse.

it could be the AC circuit. You need a scan of the engine/body control modules to be sure.

1 altinator

2 electronic fault code

3 nutral positions switch malfunction

4 bad ground

5 compressor clutch caused stall.

my guess the altinator or a fault in the PCM.

what is the year make and model of the car?

It's a ghost.

( ;