TM 9-2320-366-34-1
1-14. ELECTRICAL SYSTEM
Figure 1-16. Electrical System
In the Electrical System, a heavy duty starting motor (1, Figure 1-16) is mounted on the engine flywheel housing and
provides the cranking power necessary for starting the engine. The voltage regulator (2) maintains both a 14- and 28-
volts level for proper battery charging. The alternator (3) provides sufficient amperage to operate all electrical
components and charge the batteries during engine idling. Vehicle exterior lights are mounted in protective locations
or are protected to prevent damage. Protection is provided for lights during cross country travel. Polycarbonate lenses
are provided for all lights except the sealed beam headlights. The electrical system supplies all of the electrical power
needed to operate the vehicle and trailer. The complete Electrical System is made up of the following subsystems:
• Power Storage and Generating
• Instruments
• Engine Starting and Stopping
• Indicator Lights and Alarm
• Service Lighting
• Material Handling Crane (MHC)
• Blackout Lighting
• Troubleshooting Aid
• Accessory Lighting
• M1089 Underlift
a. Power Storage and Generating. Power storage for the vehicle consists of four 12-volt batteries. The four batteries
are divided into two sets. Two batteries in each set are wired in parallel to produce higher amperage. The two sets
are then wired in series to produce 24 volts Direct Current (DC). While the batteries can power all of the systems for
a limited time, their primary purpose is to supply power to the engine starting system. Once the engine is running, the
generating system provides electrical power for all of the systems. The engine driven alternator generates Alternating
Current (AC) which is passed through a set of rectifiers that change it into DC current. This DC current is used to
charge the batteries and is distributed to the electrical sub-systems of the vehicle. The voltage regulator adjusts
alternator output to fit the needs of the electrical system.
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