Travellers

I have just Purchased a Seat Alhambra Year 2000 with ford Radio Cassette wiring harness I have removed the Set as it displayed "TEN " and would not respond to any command, I removed three plugs to the rear one grey screened cable, one five wire connector and the black socket, I have powered up my new set Panasonic CQ-C 1300AN CD Tuner, I have sound from the set (i have tested direst to a speaker and all four outputs work fine, But I have not got a clue were to wire them into I aume I am dealing with a powered speaker harness Can any one help .........Cheers