Page 286 of 796
09-10
Alternator
The alternator charges the battery and
supplies power to each electric unit by
converting the mechanical energy to the
electrical energy.
1. SYSTEM DESCRIPTION
1) Overview
The charge system is designed to supply electrical energy to the vehicle while driving, and supplies a
constant direct current voltage by converting mechanical rotational movement to electrical energy.
The voltage regulator on the back of the alternator controls the generated voltage in all rotating ranges and
adjusts the system voltage according to the electric load and ambient temperature change.
2) System Layout (Locations)
Battery
It converts the chemical energy to the
electrical energy and supplies power to the
corresponding electric units when starting
the engine.
Page 288 of 796

09-12
Alternator (115 A)
2) Charging
The alternator uses a new regulator which has three diodes. It consists of the delta stator, rectifier
bridge, slip ring and brush.
Charging time according to vehicle conditions and environment ▶
Specification: Charging a fully depleted high-
capacity battery takes twice or more as long as
charging a fully depleted battery for small
vehicles.
Temperature:The lower the temperature is, the
longer the time taken to charge the battery.
When connecting the battery charger to the cold
battery, the amount of current the battery can
accept initially is very small. As the battery gets
warmer, it can accept more current.
Charging capacity: Charging a battery with a low-capacity charger takes longer time than charging
with a high-capacity charger.
Charging status: Charging a fully depleted battery takes twice or more as long as charging a half-
depleted battery. Since the electrolyte in a fully depleted battery consists of nearly pure water and
conductor, only a very small amount of current can be accepted by the battery initially. The charging
current increases as the amount of acids in the electrolyte is increased by the charging current.
3) Output Characteristics
Alternator (140 A)
Page 370 of 796
15-42
PTC Fuse and Relay
(13) PTC heater control
A. Overview
The supplementary electrical heater is installed in DI engine equipped vehicle as a basic equipment.
The PTC system is operated according to two temperature values measured at the coolant temperature
sensor and HFM sensor. This device is mounted in the heater air outlet and increase the temperature of
air to the passenger compartment. Because PTC system is heated by electrical power, high capacity
alternator is required. PTC does not operate during engine cranking, while the battery voltage is lower
than 11 V or during preheating process of glow plugs.
B. Components
HFM (intake air
temperature)
Coolant temperature
sensor
PTC relay 1
D20DTR ECU
PTC relay 2
PTC fuse 1, 2, 3, 40A
PTC heater
Page 403 of 796

08-51452-01
1. CHARGING SYSTEM OPERATION
Alternators use a new type of regulator that incorporates a diode trio. A Delta stator, a rectifier bridge,
and a rotor with slip rings and brushes are electrically similar to earlier alternators.
A conventional pulley and fan are used. There is no test hole.
1) Charging Time Required
The time required to charge a battery will vary depending upon the following factors:
Size of Battery ▶
A Completely discharged large heavy-duty battery required more than twice the recharging
time as a completely discharged small passenger car battery. -
Temperature ▶
A longer time will be needed to charge any battery at -18°C (0°F) than at 27°C (80°F).
When a fast charger is connected to a cold battery, the current accepted by the battery will be
very low at first. The battery will accept a higher current rate as the battery warms. -
Charger Capacity ▶
A charger which can supply only 5 amperes will require a much longer charging period than a
charger that can supply 30 amperes or more. -
State-of-Charge ▶
A completely discharged battery requires more than twice as much charge as a one half
charged battery. Because the electrolyte is nearly pure water and a poor conductor in a
completely discharged battery, the current accepted by the battery is very low at first. Later, as
the charging current causes the electrolyte acid content to increase, the charging current will
likewise increase. -
2. STARTING SYSTEM OPERATION
The engine electrical system includes the battery, the ignition, the starter, the alternator, and all the
related wiring. Diagnostic tables will aid in troubleshooting system faults. When a fault is traced to a
particular component, refer to that component section of the service manual. The starting system
circuit consists of the battery, the starter motor, the ignition switch, and all the related electrical wiring.
All of these components are connected electrically.