Ok thanks for your suggestions everyone...however I have surprising news (at least to me) on how I got this to work:
The problem was the power...and the wiring diagram looked correct and was confirmed by a Crutchfield technician to be correct. So I assumed it was a grounding issue. I had the black ground wire from the stereo connected to the metal frame in the back, while the ground wire from the converting harness was connected to a screw in the same piece of metal.
So I was messing around with both of these grounding wires, and when I touched both of the ground wires together while neither were connected to the metal frame, the stereo functioned perfectly!
Kind of an odd solution, and I dont know if it will be dangerous for the radio, but this was the only configuration that worked...