Ok I bought a stereo for a 1992 LC. I have a 1991 LC. It is a factory deck with the tape and CD player. Problem is I have three plugs in the hole where the stereo goes but none of them matcht he one plug slot on the back of the stereo? Should there be a wiring harness off the back of the stereo that will plug into my three plugs? If so will someone sell me one so I can listen to something besides my very quiet yet restrictive exhaust.