2 - 1 0 . COUPLING TRAILER TO TOWING VEHICLE (Con't).
Be sure to check SERVICE and EMERGENCY
tag markings on air hose assemblies on both
trailer and towing vehicle before connecting.
l. Unstow and connect service air coupling
(17) and emergency air coupling (19) to towing vehicle
air couplings. Open towing vehicle shut-off valves (refer
to towing vehicle operator's manual).
m. Unstow intervehicular cable assembly con-
nector (20) from clip. Connect intervehicular cable as-
sembly connector to towing vehicle electrical
n. Return two wheel chocks (1) to holders (2).
Release handbrakes by moving two handbrake levers (18) rearward.