The pig tail you refer to on the 72 radio could be the connection used for the optional casette player. This optional piece of Chyrsler sound equipment was discussed a couple of weeks ago. The casette player would have mounted on the floor of the car just under the dash board. The player requires an am/fm radio with the pig tail. It could be that you have the up graded radio necessary to install the casette option - or something is just disconnected. If you are getting sound on the AM setting I would bet there is nothing disconnected. I know from prior experience that finding after market radios and dash plates to mount them is a challenge. Good luck there. Happy motoring Dale 68 Crown Coupe 60 NY T&C, 2 door, sedan, 4 door hardtop 71 NY sedan