High Pitch Sound near alternator

I am hearing a high pitch whirring sound, and a metallic jingling sound from the belt near the alternator. When I idle the car and switch the interior fan to on, it stops. If I turn the fan knob to off, it starts back up. This just started but my battery had a jump recently and I’m not sure if that affects it. Any ideas would be greatly appreciated!

Take a piece of heater hose to listen with and isolate the sound, could be as simple as a tensioner or belt replacement. Proper diagnosis for a proper repair.

Remove the serpentine belt and spin all the pulleys by hand. Any bad ones will feel loose or rough…