zbest91tt

Hey guys, my new 91 TT I just bought came with the sony stock single disc cd player that was an option for some Z some year. The cd player did not work in my car at all when I bought it, but the unit has been tested and works. The funny round plug is plugged in to both units (cd and master), but there is no power to the cd at all. I've been told by a radio shop that I need a power plug to go from tape/radio to cd player. Is this called a "wiring harness" for the cd player? How do I get it cheap? Any help is greatly appreciated.