[63ChevC10]

Don't mean to jack this thread. I may have missed it, but does anyone have a the factory radio wiring diagram for a 76 half ton? I'm looking for the wires coming from the truck going to the radio. I have 5 wires right now...one plug with two wires (one light green and one black), and another plug with three wires (one gray, one yellow, and one black). I suspect the green and black are for the speaker?

Thanks in advance!