I wondered if someone could help this electrical idiot with a couple questions regarding an Alpine 445a Power Pack (to 143bt HU) install. I notice on all my Alpine cables that there's a blue wire with a white stripe (remote amp turn-on), but missing on my Metra 70-1721 harness. I'm told by Crutch that I don't need it but I'm confused as to why, and how not having it might affect functionality. Second, do I simply connect both ground wires, or ground both somewhere behind the dash where the amp will reside? Any grounding tips you might have, I'm all ears. Thanks, and sorry for the stupid questions.