Audio Systems: 2000 Ford Mustang Mach 460 sound system, mustang mach, ford mustang

Question
My son has a 2000 Mustang. He took the Mach 460 system out and installed an aftermarket unit. About two weeks later, his new system was stolen. We tried to re-install the Mach unit, but can not get the volume to work. With the control set on high, you can barely hear it. Is this a unit that requires an unlock code? We bought the car used and do not have an owner's manual or other papers.

Answer
one of the plugs didn' go all the way in or the amplifier is not plug right, unplug it all and check inside for bend pins
there is no code for this system a,so you need to have all the amplifiers back on the system  when you power the radio
good luck