I am in the process of changing everything over from my old J to the newer one (02 to 03). I went to swap out the radio and the newer car has the amp in the rear (which I don't car about). so I plugged in everything the way it was in the other car. Low and behold the radio doesn't power on, checked the fuse and then with a test light, there is power coming to the radio, and the little ground has been done, everything else was plug-n-play as the adapter harness has been done for years. Is there something different you have to do when the factory amp is in the car? I would just as soon get rid of it if I can. and both radios worked just fine before I changed them over, maybe something little I'm missing here.