Ford F-650 2001 Owner's Manual page 90

Seating and safety restraints
• 4–door CrewCab
To lower the shoulder belt height, push the button and slide the height
adjuster down. To raise the height of the shoulder belt, slide the height
adjuster up. Pull down on the height adjuster to make sure it is locked in
place.
Position the shoulder belt height adjusters so that the belt rests
across the middle of your shoulder. Failure to adjust the safety
belt properly could reduce the effectiveness of the seat belt and
increase the risk of injury in a collision.
Lap belts
Adjusting the center lap belt
The lap belt does not adjust automatically.
The lap belt should fit snugly and as low as possible around the
hips, not across the waist.
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