I believe it s called the generator warning light?
It turns on when I start the car. Can I still use the car? dangerous?
Where do I start to fix it ?
Thanks

The light should come on when you start it, then go off once the car is running.
If its staying on then your charging system is not working. Which means your alternator is not charging your battery. Not dangerous will just drain your battery and your car won't start.
Could be a bad ground or connection, broken/loose alternator belt, bad voltage regulator, bad alternator.
First check ground and battery connections, alternator belt, loose or broken wires to the alternator. Could try swapping voltage regulator if you have an extra, next would be have the altnenator tested.

Hope this helps
Jeff

It helps.
Now I have a starting point.
Thanks

You can drive just fine until the battery discharges and the car stops running.

Not sure I want to do that.