Hi, I bought a Pioneer DEH-X5500HD reciever for my 2002 Chevy Trailblazer LT.

I asked the guy at the car shop for which wiring harness I needed. He suggested the
Metra CF-WHGM3. I connected the wires of the cars harness to the Pioneer harness, checked all colors .

it didnt work, didnt turn on, what am I missing. The trailblazer also had a black harness that couldnt connect to the reciever...