Generator light on

I currently have a 1962 chevy belair. It has the old generator style instead of the alternator. The light stays on permanently just recently and now it doesn't start. I can jump it with my other vehicle and leave it running but once I turn the car off it goes out.

I recently bought the car and when purchased the generator light would come on, but once you got the rpm's up it would go off just recently it just started to stay on permanently.