Helical

I bought a metra kit and a wire harness for my pioneer double din. I have wired everything but have a few wires left open. I plugged the harness into the main harness from the car and it gets no power. I noticed that a red ignition wire is missing from the aftermarket harness and I have no clue where the 12v yellow constant power wire. I may just order the Scosche MZ01SR harness and try again.

Is there a step by step guide?