The cord is installed on 6.0L Powerstrokes originally sold in the following states: Alaska, Colorado, Iowa, Maine, Minnesota, Missouri, North and South Dakota,Wyoming and our neighbor to the north; Canada
Sometimes the cord is zip tied up pretty high you may have to remove the grille to access it from the top.
Additional areas to check;
Pass side in bumper below radiator.
Just curbside of the passenger side towhook.
Possibly between radiator and grill/bumper by passenger side foglight(if equipped)
Put your hand in through the passenger side tow hook hole in the bumper. Feel/look to the right and up a bit. There is a black ribbed wire loom sheath folded over on itself and tied with a black tie-wrap. The plug itself has a black plastic cover snapped on it, which has a restraining strap that goes around the wire loom. If you cut the tie-wrap, you can bring the plug down to the level of the hole to get at it.