When I got it, he said the reason nothing works is because he thinks its the factory amp. so i took everything out (except the amp, cant get it out dont know why) put in new speakers, and have a cd player to put in just have to go get the wiring harness and dash kit from my old work, so is it going to work with the factory amp still in there? or should i take it out? how do i re-route the wires and everything..?