Yes


The warning light exists as an easy way to power the field coils so the alternator will charge from very very low revs.

When you spin the alternator fast enough it will "self energise".

So when the alternator is functioning correctly it outputs a voltage from the field coils that matches the voltage trying to be fed to the alternator. This means that electricty won't flow and the light goes out.

Some cars alternator seem to fail but its just the bulb thats gone


Alex