Audio Systems: 2004 avalanche speaker system, fuse box, body control module

Question
recently jump started vehicle and had radio on.  after jump starting the speakers would not work.  the radio comes on and shows channel and song playing.  read the owners manual after jump starting and found out that  you are to turn everything off first or damage can occur. do  you know what i need to do to get things working?
         Daniel

Answer
check the fuse for the factory amplifiers  it is in the fuse box if that don't work the problem is on the data bus from the vehicle siganl comes from the body control module
vehicle needs to go to the dealer  they are the only ones with the gm scann tool for the audio system