TM 5-3805-298-23-1
0004
ELECTRICAL SYSTEM
0004
Batteries
0004
Two 12V batteries, one on each side of the machine, are located behind the rear tires and are standard equipment.
The batteries are connected in series to output 24V for starting, charging, and operation of the machine.
If the machine is equipped with the optional arctic heater, four additional 12V batteries may be located with the
standard equipment batteries. The arctic heater batteries are connected in series with each other and in parallel
with the standard equipment batteries to provide additional power for cold starts and to run the arctic heater.
0004
CAUTION
Never operate the alternator without the batteries in the circuit. Making or breaking an
alternator connection with a heavy load on the circuit can cause damage to the regulator.
Failure to follow this caution may cause damage to the equipment.
The alternator is a 24V, internal regulator, self rectifying charging unit. The alternator is mounted on the front of the
engine and is driven by the accessory drive belt. When the engine is running, the alternator provides enough
current to run the machine's electrical systems and charge the batteries.
NATO Slave Receptacle
0004
The NATO slave receptacle is located on the battery box at the left rear of the machine. The NATO slave receptacle
provides a means to jump-start the engine.
Starter
0004
The transmission ECM will activate the starter relay to energize the starter motor when certain conditions are met.
The transmission ECM monitors the transmission control lever position, the park brake switch, and the start switch.
If the transmission is in neutral, the park brake is ON, and the ignition switch is in the START position, the transmis-
sion ECM will activate the starter relay.
Electronic Control Modules
0004
The machine has two electronic control modules (ECM's), an engine ECM and a transmission ECM. These mod-
ules operate with 24V, but may output smaller reference voltages to various sensors or solenoids on the machine.
Both modules share a common data link which allows for sharing of information between modules and for use of
the electronic technician (ET) for diagnostics.
PRIMARY POWERTRAIN SYSTEM
0004
The transmission is an electronically controlled power shift transmission. The transmission has four forward
speeds and three reverse speeds. Power is transmitted from the engine, through the flywheel, to the torque con-
verter, transmission, driveshafts, front and rear differentials and final drives.
The transmission ECM regulates shifting of gears. The transmission ECM commands six solenoids. These sole-
noids control hydraulic oil flow in the transmission controlling direction and gear selection of the transmission. The
transmission ECM monitors the following switches and sensors to determine which gear the transmission should
be in:
Start Switch provides battery voltage to the transmission ECM when the switch is placed in the ON position.
Transmission Control Lever provides a signal to the transmission ECM indicating which gear has been
selected.
Transmission Output Speed Sensors A and B (TOS 1 and TOS 2) provide the transmission ECM with the
output shaft speed of the transmission.
Intermediate Speed Sensors A and B (ISS 1 and ISS 2) provide the transmission ECM with the intermedi-
ate shaft speed of the transmission.
0004-4
