The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench 1967-72 am/fm help

I have a 67-72 delco am/fm radio to go in my '68 burb, I had an antenna issue but solved that, now I cannot get the radio to play on am or fm side. It powers up but no sound.There are only three wires on the back of the radio,a red(power) a green and a black.I have the original single dash speaker in the truck and/ or two newer speakers(8ohm)where do the green and black wires from the radio go, tried those to the speakers but no luck. HELP!