jasejase - thanks for the reply. I had found Jazzy's link to Audacity and used that to burn the 'silent' CD, 180 minutes.
car_cursed/jazzymt - thanks for the replies.
The CD that came with the mod board seemed to be recognized, but the head kept jumping back and forth across the CD.
The CDs that I burned, AIFF, WAV, & MP3, all spun normally and the CD timer kept track of the time.
Even though they spun normally, it seems something was not being recognized and therefor nothing was being passed from the CD player to the radio/amplifier.
I'll be getting a CD cleaner disk today to try. I'll post results.