Does ANYONE know what the hell this pigtail is for? Best buy & Circuit City have no idea. Called panasonic, they said it might be for a "DC to DC converter" - whatever that is. When i pulled it out of my freinds car it was plugged into a small black box. I was a in a hurry and since i never saw such a thing i didnt think it was important. The unit powers on and functions fine - no sound from speakers. Its not a wiring issue, i put it a different vehicle with different harness. Preouts work as well. I need to know where I can find the black box, the part # for it, or at least an instruction manual. Owners manuals for these have no wiring or installation instructions. PLEASE HELP
