Lets not over complicate this... its the belt tensioner. They are lazy f*ckers on a lot of magnum engines & need to be oiled up and then bent back toward the passengers fender with a little help from a 15 mm wrench to get them back into proper belt tension.

If you hear a grinding noise in the front of your motor then its the center slave pully's bearing between the ac pump & alternator. But the good money is on a lazy tensioner pully that needs a kick in the ***.