Why does my radio turn on but no sound?
Check each set of wires and speakers to be sure no wire or lead is connected to a chassis ground. The radio will see this as a short and turn off the internal amplifier causing the on but no sound issue. Each speaker connected to the radio needs dedicated positive and negative leads from the radio to each speaker.
How do you unmute a Pioneer radio?
To unmute your Pioneer car stereo:
Press and hold the source button until the stereo turns off. Press and hold the function button until the unit beeps. Continue to press the function button until the telephone appears.