CDR 220 - Radio Not working

[flying scot]

Hi - I have a 2001 car - it has the CDR220 installed but the radio does not work. The CD works fine. The previous owner stated that it all worked fine until she removed the digital radio (sirius or XM...?). I like the original installation however if its going to cost a significant amount to sort I might as well get a modern unit from Crutchfield - $100 with an IPOD plug-in and bluetooth. Can anyone advise on the likely source of this problem?

Much tx
Jim