Check the OEM back connection first to see if customer got the right harness.

The landcruiser amplifier some will control by the decorder box and some will control by the amp connection.

If the console setting cannot be changed, and when put back to the OEM it has sound it's probably the amplifier didn't open.

Find the above connector, the third pin beside the orange one connect the power or ACC to that pin to open the amplifier.