Ford 2010 F-150 Owner's Manual page 208

Seating and Safety Restraints
3. Slide the tongue up the webbing.
4. While holding both shoulder and
lap portions next to the tongue,
route the tongue and webbing
through the child seat according to
the child seat manufacturer's
instructions. Be sure that the belt
webbing is not twisted.
5. Insert the belt tongue into the
proper buckle (the buckle closest to
the direction the tongue is coming
from) for that seating position until
you hear a snap and feel the latch
engage. Make sure the tongue is
latched securely by pulling on it.
208
2010 F-150 (f12)
Owners Guide, 1st Printing
USA (fus)