TM 5-3805-248-23-1
THEORY OF OPERATION - CONTINUED
0003 00
ELECTRICAL SYSTEM
0003 00
The electrical system has three separate circuits: charging, starting and low amperage. The batteries, circuit breakers,
ammeter, cables and wires are common to each of these circuits.
The charging circuit operates when the engine is running. The alternator generates electricity for the charging circuit. A
voltage regulator in the circuit controls the electrical output to keep the batteries at full charge. The starting circuit is in opera-
tion only when the start switch is activated.
The low amperage circuit and charging circuit are both connected through the ammeter. The starting circuit is not con-
nected through the ammeter.
1.
2.
Starter Motor. The starter is a 24-volt DC, series-wound electric motor, with externally mounted solenoid.
3.
Lights. Four headlights, two side worklights and two turn signals are mounted at front of machine. A single blackout
light is mounted below headlight cluster on front-left side of machine. One worklight is mounted on rear of tractor por-
tion allowing lighting to bowl/apron cutting edge. Two stop/tail lights, two blackout stop/tail lights and two turn signals
are mounted at rear of the scraper above push block. Lighting sequences are controlled from operator compartment
instrument panel. A floor-mounted dimmer switch is also located in operator compartment.
Batteries. Two 12-volt, 220-ampere hour batteries wired in series, give 24 volts DC to the electrical system.
4.
5.
Instrument Panel.
a.
Instrument panel gages and indicators.
(1)
Low air indicator. Indicates low air pressure in air system.
(2)
Water temperature gage. Indicates engine operating temperature. Electrically connected to sending unit
mounted on engine.
(3)
Hour meter. Indicates number of hours engine is registering oil pressure (time running).
(4)
Ammeter. Indicates rate of charge from alternator.
(5)
Converter retarder temperature gage. Indicates temperature of oil in hydraulic retarder.
WATER
HOUR METER
LOW AIR
TEMPERATURE GAGE
INDICATOR
CONVERTER/RETARDER
394-155
AMMETER
TEMPERATURE GAGE
0003 00-4
