Hello I changed a non-factory cassette radio that was in the vehicle when I bought it to a cd player. But now there is no sound. I have connected all the wires. I believe that I am missing something very basic but not sure what it might be any help is welcomed. Thanks.

Check all your connections. Check the fade and balance controls on the radio.

I had a similar problem. I remember having to attach a blue? power wire for the amplifier I think. Do you have the premium sound system?