I knew this day would come...post #1 of #3 across the FABO forum...

Constant power goes to the fuse box. It's been awhile but I think the factory radio plug on my had 2 wired. A red switched hot wire and yellow for the backlight on the radio lense. I think the radio ground was through the body of the radio to the dash.

So, if I am remembering all of the correctly. You will run the yellow/Constant power wire to the fuse box. The red switched hot to the factory radio plug. And finally run the black to chassis ground. The factory yellow wire isn't needed from what I remember.