[brucepick]

I found the yellow + black wire at a 9-pin connector near the driver's side hood hinge. I think maybe only 8 wires there, but it's a 3x3 layout. That connector might still be there on your Gen 7, mine is Gen 6.

Other people have tapped into the computer's connectors. I'm just not comfortable working on those connectors with dozens of tiny pins and wires. But I know it's been done successfully.