ELECTRICAL SYSTEM - TM-9-2320-366-20-10077

TM 9-2320-366-20-1

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.