I ran into a similar problem installing a sony in our old Chevy truck. Hooked everything up and... Nothing. So, I read the book and called the "help" line and etc. Then I found out that the radio had to be "configured" in a menu for 2 channel stereo or 4 channel stereo on the display. I went thru all that crap and it has worked ever since. I also noticed that the radio didn't have fuses anywhere in the output section. The response I got from the "tech support" guy was that the radios no longer have fuses- but if they see too low a resistance- they "shut down" the output amp like a fast relay to prevent a bunch of warranty repairs from peple crossing wires when installing them. Good luck.