Thanks for posting this problem and the solution. I am hoping it is the exact issue that I am having with our crossfire. Previous owner said the radio worked at one point but stopped producing sound. First thing we checked was fuse number 23 for the amplifier. That fuse was good but I don’t know which other fuses to check. I have a few aftermarket head units and a Metra wiring harness so I could swap those out to do some troubleshooting without spending more money but I definitely did not want to buy another factory amp without knowing it would solve my problem. when we bought the car I figured that if all else failed we could run new speaker wires from an aftermarket head unit and bypass the amp without cutting any wires. I prefer to use the factory amplifier and wiring without cutting and splicing except as absolutely necessary. Now that I know what to test it’s just a matter of finding someone who knows what they are doing to do the actual testing.