Mine worked for many years with this exact setup... in fact, it was before mp3 were so popular... so I was using a sony diskman player lolll... but that was between 5 to 8 years ago... I wonder if it's still in working order... where ever that car is now...lol
So, yeah, as ^^^ he says, take it out and open it up to check all the connections, and see if any circuits are burned up... or post in the wanted section to see if anyone has a working one somewhere in a bucket of parts or on the garage floor....