TM 9-2320-260-20
1-22. SPECIAL PURPOSE BODIES SYSTEMS OPERATION (Contd)
c. Auxiliary Trailer Power Systems Operation (M818).
The trailer receptacle and air coupling are used on the M818 tractor body to power lights and brakes
of a towed semitrailer. Major components are:
A ELECTRICAL CABLE - Connected to electrical receptacle of a semitrailer to power its electrical
system.
B
SERVICE AIRBRAKE HOSE LINE - Connects to service airbrake coupling on semitrailer to
provide air to service airbrake system.
EMERGENCY AIRBRAKE HOSE LINE - Connected to emergency airbrake coupling on
C
semitrailer. The trailer emergency brake system activates when primary air system fails.
D AIRBRAKE HOSE COUPLING VALVES - When in ON position. activates trailer brakes
to truck brakes. In OFF position, deactivates trailer brakes-from truck brakes.
1-68
