Needed: Radio wiring diagram for a 82' c10

[ECU PIRATE]

Greeting Men,

Would any of you members happen to have a radio wiring diagram for an 82' C10? I am in the process of trying to plan out my audio system for my 82' SWB but, the guy I bought my truck from seems to have butchering the wiring in the dash. The only thing that was connected when I pulled the radio this morning was the antenna which is conspicuosly mounted on the driver's side of the cowl.

I did manage to the locate the original connection for the center dash speaker but, I may opt to run (2) 3 1/2's instead. I managed to find (2) original rear speakers out of an 85' (bought just for the mounts), that I am going to throw into the mix......Many thanks for your assistance