hi all new here. have a 2001 fiat punto sporting 1.2 16v

it has the standard blaupunkt headunit with built in sat nav at top, then a 5 cd changer the bottom. however wen i press CD-C on the head unit, i get the message " NO MAGAZINE/MAGAZINE EMPTY". So i have no cd player in my car. I then decided to get a blaupunkt to ipod cable and replaced the cd changer with the ipod cable. bet i then get a "NO AUDIO CD INSERTED" message on the headunit???

does the top head unit have an AUX out in the back??

somebody please help and advise, thank you