On my 2011 Legacy Limited with HK installed new Pioneer head unit with Crux Steering wheel control. Used 20 pin wire harness from Crux to Pioneer harness. Powers up steering wheel controls work, Carplay activates and FM signal works but no sound. Double checked connections on harness and all seem to be correct and making contact. I don't know if there is another step I'm missing because of the factory amp?? Any thoughts would be appreciated.