99 galant 2.4l sohc Main drive pulley lose

Hello TGC I own a 99 galant I bought her used but she is the bet car Ive ever owned and I love her.
She has keep me out of trouble by outrunning some. Keep me warm when I needed a place to sleep.
She has only ran out of gas on me once. She has 190thousand plus miles on her, and hates to be worked on, yea I know sounds like im off my rocker.! Well today and with no warning the break and battery light came on.
Also a strange noise from engine compartment. the main drive pulley is lose. is this something that happens a lot or is something else going on..and what should I be looking for..please if any one has a suggestion or an idea I'm all ears....Thank You Chris Hershberger