TM 9-2320-360-10
1-14. ELECTRICAL SYSTEM
The electrical system is a combined 12 Vdc/24 Vdc system. Four 12-volt storage batteries (1) are
connected in series-parallel with the negative terminal grounded. The starting motor (2) operates directly
from the 24 Vdc source through the engine start switch (3). A belt-driven alternator (4) having a capacity
of 130 amps maintains the charge on the batteries for the 24 Vdc system. A second belt-driven alternator
(5), having a capacity of 145 amps, maintains the charge on the batteries for the 12 Vdc system. The 24
Vdc source supplies electrical power to operate starter, Central Tire Inflation System (CTIS), fuel/water
separator, air dryers, trailer lights, and ether injection system. The 12 Vdc source supplies electrical
power to operate HET Tractor lights, trailer lights, warning lights and gages inside cab, and windshield
wipers and washer. There are two BATTERY gages (6). One shows the voltage output for the 12 Vdc
system, the other shows the voltage output for the 24 Vdc system. The HET Tractor electrical circuits are
protected against overloads by automatic reset circuit breakers (7). Wiring harnesses are used to carry
current to operate equipment and accessories.
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