GMC 1999 Sierra 1500 Pickup Owner's Manual page 53

Securing
a Child Restraint in a Rear Outside Position
(Extended Cab)
1
K2145
You'll be using the lap-shoulder belt. See the earlier part about the top strap
i f the child restraint has one.
1. Put the restraint on the seat. Follow the instructions for the child
2. Secure the child in the child restraint as the instructions say.
restraint.
AM160150
3. Pull out the vehicle's safety belt. Make the belt as long as possible by
tilting the latch plate and pulling
it
along the belt.
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