ELECTRICAL SYSTEM - TM-9-2320-270-20-10036

TM9-2320-270-20-1

ELECTRICAL SYSTEM

When the key switch is turned to START, the voltage from the batteries is sent to the starter. When the

starter is energized, the pinion engages with the torque converter ring gear and engine cranking

occurs. After the engine starts, the pinion is disengaged from the torque converter gear. When the

engine is running, the alternator provides a source of electrical current for maintaining the storage

batteries in a charged state and supplies current to the other electrical components (lights, switches,

gages, sending units, etc.). When the key switch is turned to ACC,the voltage from the batteries

goes to the lights, switches, and sending units. When the key switch is turned to IGN, the voltage from

the batteries is sent to the shift controller switches, the buzzer, and the instrument panel gages.

Key Switch Located in the cab, the key switch is used by the operator to start the engine and to turn

on power to the electrical components on the vehicle (lights, switches, gages, sending units, etc.).

The four positions the switch can be turned to are: ACC, OFF, IGN, and START. When the switch is

turned to OFF, there is no power in the vehicle.

Batteries - The lead-acid storage batteries are electrochemical devices for changing chemical energy

into electrical energy. There are four 12-voIt batteries in the electrical system. They are connected in

series-parallel to provide a total system voltage of 24 volts.

Starter The starter has a 24-volt, heavy-duty motor, and a solenoid-operated, positive engagement

shifting mechanism. When the starter is energized, the pinion gear of the drive assembly is moved into

mesh with the torque converter ring gear by the shift lever. When the engine starts, pinion over run

protects the armature from excessive speed until the switch is opened and the pinion is disengaged.

Alternator The alternator is belt driven off the engine. As the alternator rotates, alternating current

is generated by magnetism in the rotor. The alternating current is changed into direct current by a

rectifier, and the amount of direct current sent out is controlled by a built-in regulator.

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