Engine Electrical System

TM 9-2320-312-24-2

Systems Operation Section

Both the low amperage circuit and the charging

circuit are connected to the same side of the

NOTICE

ammeter. The starting circuit is connected to the

When boost starting an engine, the instructions in Sys-

opposite side of the ammeter.

tems Operation, "Engine Starting" should be followed

in order to properly start the engine.

NOTICE

This engine may be equipped with a 12 volt starting

Never operate the alternator without the battery in the

system or a 24 volt starting system. Only equal voltage

circuit. Making or breaking an alternator connection

for boost starting should be used. The use of a higher

with heavy load on the circuit can cause damage to

voltage will damage the electrical system.

the regulator.

The Electronic Control Module (ECM) must be dis-

connected at the "J1/P1" and "J2/P2" locations before

welding on the vehicle.

Engine Electrical System

The electrical system has three separate circuits:

Charging circuit

Starting circuit

Low amperage circuit

Some of the electrical system components are used

in more than one circuit. The following components

are used in each of the three circuits:

Battery

Circuit breaker

Ammeter

Battery cables

The charging circuit is in operation when the engine

is running. An alternator generates electricity for the

charging circuit. A voltage regulator in the circuit

controls the electrical output in order to keep the

battery at full charge.

NOTICE

The disconnect switch, if equipped, must be in the ON

position in order to let the electrical system function.

There will be damage to some of the charging circuit

components if the engine is running with the discon-

nect switch in the OFF position.

If the vehicle has a disconnect switch, the starting

circuit can operate only after the disconnect switch

is put in the ON position.

The starting circuit is in operation only when the

start switch is activated.