This thread is probably dead, but i installed an aftermarket double din, (original stereo only let 1 speaker work) wired everything up correctly, had power and no sound. Its an 02 tahoe non bose, found factory amp behind glove box, so essentially cant i just bypass factory amp, using the 60w x4 head units power by wiring into the harness that leaves factory amp to the door speakers. Keeping original speakers for now btw. Or is their an easier way like jumping a 12v to the original factory amp?. Also installing subs and amp for them as well but thats not my issue at hand.