Chevrolet 2003 Blazer Owner's Manual page 16

On two-door models with an inside mounted spare tire,
the driver's side rear seat head restraint must be
lifted and held upright as the seatback is raised.
Otherwise, the head restraint will hit the spare tire and
prevent the seatback from properly latching.
Push and pull on the head restraints to check that they
have locked in the upright position. If they haven't,
see your dealer for service.
If the seatback isn't locked, it could move
forward in a sudden stop or crash. That could
cause injury to the person sitting there. Always
press rearward on the seatback to be sure
it
is
locked.
A safety belt that is improperly routed, not
properly attached, or twisted won't provide the
protection needed in a crash. The person
wearing the belt could be seriously injured.
After raising the rear seatback, always check
to be sure that the safety belts are properly
routed and attached, and are not twisted.
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