This is my second post. My wife's car is a 1998 Cadillac Deville Sedan. It came with an AM/FM/Cassette that worked fine. She wanted to add CD, so I bought and installed the correct OEM AM/FM/Cassette/CD HU, this is a delco HU and the HU I replaced was also Delco. Took it to Cadillac and they unlocked it ($47.50 plus tax). All the features seem to work properly, BUT NO SOUND. I was even able to set the clock. Do I need a external amplifier or will I have to rewire the car? I am at a loss. I am thinking of adding the 12 disk remote CD changer (OEM), in the trunk. I am not sure if I can do that and still have a single disk HU up front? Thank you. God Bless you and yours.