Thanks for the reply. I tested the ignition wire and it does have voltage when "on" and none when "off." Which makes me think there is something else going on.
Does anyone know if there is a factory reset switch on these lovely Delco RDS radios? At this point I'd be happy just to cut my losses and go back to having a radio only that I could at least hear. My factory unit is not "Locked" or "Secure," and everything works except there is no sound. Any help is greatly greatly greatly appreicated.
Thanks,
Nathan