Electical problem: intermittent stereo sound

When the electical system is turned on or the truck is started, the stereo always indicates that it is running, but no sound comes from the speakers. Dealer replaced stereo without improvement. Happens intermittently, averaging 4/5 times. Suggestions?

I had the same problem on my 98 pickup. They had to put in another wire harness for the stereo and it is better now. A ton of other things wrong but that works for now.