Make sure all electrical power is disconnected before performing any maintenance on the electri-
cal system. Serious injury or death may result if proper precautions are not taken.
a. The M129A4 and XM1063 semitrailers are equipped with two intervehicular cable receptacles,
located in the voltage convertor box and cover assembly (M129A4) and resistor box and cover assembly
(XM1063) at lower left corner of front of semitrailer.
b. The 12-pin, 24-volt receptacle (2) is located to the left of the 7-
pin, 12-volt receptacle (1)
c. A system of resistors (XM1063) or circuit breakers (M129A4)
make it possible to use a towing vehicle with either a 12-volt or 24-volt electrical system.
d. Refer to semitrailer wiring diagrams before connecting any
disconnected wires (pages 4-58 through 4-66).