finding radio plug tips

I put in a hew H and M harness from year one. The dash was installed and all interior all put in. I didn't hook up the radio, I wanted to get car driveable before winter and installing the radio was to be a winter project. I have radio ready to put in, but can't find the radio plug on the harness. I compared it to the original as it was installed on the dash so I am sure it was there. Any tips for locating it? Maybe which set of wires it is coming out from. It has been a bit since I looked for it. I did a search and found some info to use tomorrow eve.
Car is a 70 dart with 71 dash and harness.
Thanks