Ford Mercury Villager 1997 Owner's Manual page 163

6. Before placing the child in the child seat or infant carrier, use
force to tilt the seat from side to side, and tug it forward to
make sure that the seat is securely held in place.
Testing the security of the child seat
7. Check that the retractor is in the automatic locking mode.
Try to pull more belt out of the retractor. If you cannot, the belt
is in the automatic locking mode.
8. Check to make sure the child seat or infant carrier is properly
secured prior to each use. If the safety belt is not locked,
repeat steps 3 through 6.
NOTE: When the lap/shoulder belt is unbuckled and allowed
to retract completely, the retractor will switch to the
vehicle sensitive (emergency) locking mode.
Seating and Safety Restraints
159