Hey gus738, yea i'm active been busy though. I made a paint diagram for you. It's really terrible, but hopefully you can get the idea. Yes you need an amp bypass AND a radio harness.
Speaker wires coming from the speaker harness on the factory amp (under the shifter) go to the amp bypass, the red, yellow, and black wires are used in the radio harness only. So basically the radio harness provides the unit with power, and the amp bypass provides the unit with sound.
