What are the signs of a bad alternator?

There are many common warning signs of a failing or bad alternator:

Dim or flickering headlights and interior lights while the engine is running.

Dead car battery or the battery constantly going flat.

Dashboard warning light, usually the battery or ALT light, stays on.

Strange whining or grinding noise coming from the engine bay.

Slow or difficult engine starting.

Electrical issues such as weak air conditioning, malfunctioning radio, and faulty power windows.

Burning rubber smell caused by a slipping alternator belt.