RAM 2013 CHASSIS CAB 3500 Owner's Manual page 107

Tether Strap Loop With Center
Head Restraint In Raised Position
2. Place a child restraint on the seat and adjust the tether
strap so that it will reach over the seat back, under the
head restraint, through the tether strap loop behind
the seat and over to the tether strap loop behind the
center seat.
THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 105
3. Pass the tether strap hook under the head restraint
behind the child seat, though the tether strap loop
behind the seat and over to the center tether strap
loop.
Tether Strap Through Outboard Tether Strap Loop
2