on a 97 its integrated into the door lock inside the door when the latch closes it turns off the chime thats part of your problem. The other is the chime itself with the key removed it shouldn't chime so that indicates your lock cylinder is off somehow. There is a pice inside that contacts metal when the key is inserted and closes the chime circuit if its out of alignment it will contact all the time and chime with the key in or out. Mine is messed up the other way it doesn't chime unless the key has pressure on it but i hate the chime so i never fixed it.
New DD-2009 Ford Mustang GT/CS candy apple red.
(sold)2003 XLT Tan 3.0L V6 5-speed, Lots of mods.