1987 Sierra Classic Radio Help

[J40man]

I picked up a 1987 GMC Sierra Classic, started taking it apart and noticed that the stereo is completely removed. No radio, speakers, or any wires. Can't seem to find where I'd plug in a wiring harness for I can install a radio. Does anyone know where exactly the plug would be or how to wire a radio into the truck without having a harness?

 

[silverscottsk10]

Orange is constant 12v for memory
Yellow is accessory/ignition 12v
Black ground
Speaker wire is whatever color you want to run
The antenna wire is a thick black wire with an end that looks like a headphone jack
Find the cigarette lighter power wire for your orange constant
Run the ignition on wire from radio to ignition space in fuse block, ground it, run your speaker wire (why not replace the old), hook up antenna and set your stations