Chevrolet 1997 Blazer Owner's Manual page 36

2. Push the latch plate into the buckle until it clicks.
Pull up on the latch plate to make sure it is secure.
When the shoulder belt is pulled out all the way, it
will lock.
If
it does, let it go back all the way and
start again.
If the belt is
not
long enough, see "Safety Belt
Extender" at the end
of
this section.
Make sure the release button on the buckle is
positioned
so
you would be able to unbuckle the
safety belt quickly if you ever had to.
3.
To
make the lap part tight, pull down on the buckle
end
of
the belt
as you pull up on the shoulder part.
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