If you find cracks in the ribs and a certain audible noise from the AC
You don't repair a serpentine belt. You replace the worn or broken belt with a new one.
Either the belt is worn out or the tensioner is defective.
A serpentine belt has an idler pulley on is to keep it tight at all times. If your serpentine belt is loose, then something is worn out. Its possible the idler pulley is stuck in its bracket so it cannot move or the spring on it is worn out.
No, there is no connection.
Yes a loose or badly worn belt will not drive the compressor correctly and then the belt will break
You do not tighten a serpentine belt. It has a tensioner that keeps it at the correct tension. If it is loose, either the belt is worn and needs replacing or the tensioner is defective.
Worn serpentine belt and/or belt tensioner.
Worn bearing and new belt is tighter than worn one?
It is important to have proper fitting parts on a car. A serpentine belt will fall off because it is worn out, or because it is too big for the car.
either the belt is worn to the point of breaking or its very loose
You don't. The belt tension is automatically adjusted via a spring loaded tensioner. If the serpentine belt is noisy or worn out prematurely. replace the tensioner. The belt should be inspected for cracks and other signs of wear. Replace worn out belt(s) before they break leaving you stranded.
no. no relation at all