Ford 1999 Windstar Owner's Manual page 135

Seating and safety restraints
4. While holding the shoulder and
lap portions together, 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 for that seating
positions until you hear a snap and
feel it latch. Make sure the tongue is
securely latched to the buckle by
pulling on the tongue.
6. While pushing down with your
knee on the child seat pull up on
the shoulder belt portion to tighten
the lap belt portion of the
combination lap and shoulder belt.
135