Im confused why you dont just run new wiring. you simply need 12v+ fused constant, 12v+fused switched with a filter in it, ground, and then speaker leads. if the factory harness is so hacked, "chopped off above the gas pedal" just redo it and make it clean.

 

I'm a little confused too. When you say the entire harness is chopped off above the gas pedal, are you talking about the wiring to the stereo, or all the wiring. If it's just the wiring to the stereo, I'd run new wiring. I'm not a big fan of stock stereo wiring anyway. If it's more than the stereo wiring, I'd suggest looking at a junk yard or LMC (or similar) for a complete wiring harness.

 

I did end up finding the harness and just extended to where it needed to be. Got a new deck in and both the speakers in the dash and in the rear doors work. What I need help with now are the speakers above the tailgate. I pulled them and they aren't wired into anything. Where should I start looking for whatever remainder of those wires there may be? Physically where were they ran? I'm assuming they're tucked under the interior somewhere