wiring a radio into a 1976 c10, which stock wires are which?

[aleighs1990]

I am wanting to install an aftermarket radio I've had for a while, in my 76 c10 that I haven't had long. It appears there are 5 wires (2 plugs) for radio hookup. I know that the green and black in one plug are for the dash speaker, but which of those wires is which (+/-)? Also, the other plug has a yellow, a black, and a grey wire. What are each of those wires for. Also, I don't have money for more speakers right now, so which channel, of the 4 my radio has, would sound best hooked up to the one speaker?

[zieg85]

Green + black -, yellow-power black-ground and grey is dash lights

[bake74]

     Welcome to the site.  Here is a pic.


   

 You can find the all the wiring diagrams for your 76 in the tech section under wiring diagrams in the search window, and the whole radio pic  here in the cab interior page.