Equipment Differences and Technical Data (Cont)
1-12. EQUIPMENT DATA (CONT).
Table 1-3. Load Classification
With Loaded Trailer
M983 w/o crane
C-48 (towing loaded M985)
C-38 (towing HEMAT
Section III. TECHNICAL PRINCIPLES OF OPERATION
Vehicle Operation Systems
1-13. SYSTEMS INTRODUCTION.
All M977 (FHTV and Non-FHTV) vehicles
contain three functional systems. They are the electrical system, air system, and
hydraulic system. This section explains the overall operation of the functional
1-14. ELECTRICAL SYSTEM.
The electrical system (fig. 1-16) is a 24 Vdc
system. Four 12 Vdc 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 24 Vdc
alternator (4) maintains the charge on the batteries. The alternator has a
capacity of 65 amps (M983 -- 100 amps) or 130 amps. The AMPERES gage (5)
shows the alternator output. The BATTERY gage (6) shows the state of charge of
the batteries and alternator voltage output. The vehicle electrical circuits are
protected against overloads by automatic reset circuit breakers (7) located below
the heater compartment panel. Wiring harnesses are used to carry current to
operate equipment and accessories.