Rotation of the excited field coil generates AC volt-
age in the stator.
This alternating current is rectified through diodes to
DC voltage having a waveform shown in the illustra-
tion above.
The average output voltage fluctuates slightly with
the generator load condition.

When the ignition switch is turned on, current flows in
the field coil and initial excitation of the field coil
occurs.
When the stator coil begins to generate power after
the engine is started, the field coil is excited by the
output current of the stator coil.
The generator output voltage rises as the field cur-
rent increases and it falls as the field current
decreases. When the battery positive voltage (gener-
ator S terminal voltage) reaches a regulated voltage
of approximately 14.4 V, the field current is cut off.
When the battery positive voltage drops below the
regulated voltage, the voltage regulator regulates the
output voltage to a constant level by controlling the
field current.
In addition, when the field current is constant, the
generator output voltage rises as the engine speed
increases.

AK704219

Generator

ECM

CAN
communication

G
S
L
FR

Battery

Generator
malfunction
light

Combination
meter

Stator coil

Voltage
regulator

Field coil

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-3

GENERAL SPECIFICATIONS

M1161000200518

Item

Specification

Type

Positive battery positive voltage sensing

Identification number

A3TL0081

Part No.

1800A155

Rated output V/A

12/120

Voltage regulator

Electronic built-in type

SERVICE SPECIFICATIONS

M1161000301024

Item

Standard value

Limit

Regulated voltage
(Ambient temperature at
voltage regulator)

−20° C (−4° F)

14.2

− 15.4

−

° C (68° F)

13.9

− 14.9

−

° C (140° F)

13.4

− 14.6

−

° C (176° F)

13.1

− 14.5

−

Generator output line voltage drop (at 30 A) V

−

Maximum 0.3

Output current

−

70 % of normal output
current

Field coil resistance

Ω

Approximately 2

− 5

−

Brush protrusion length mm (in)

−

Minimum 2 (0.08)

CHARGING SYSTEM DIAGNOSIS

M1161000700535

TROUBLESHOOTING HINTS

Generator malfunction light does not go on when the ignition

switch is turned to ON, before the engine starts.

• Check the generator malfunction light.

Generator malfunction light does not switch off after the engine

starts.

• Check the IC voltage regulator inside the generator.

Discharged or overcharged battery.

• Check the IC voltage regulator inside the generator.

TROUBLESHOOTING GUIDE

The charging system troubleshooting guide is shown in the fol-
lowing steps.

STEP 1.
Q: Is the battery in good condition? (Refer to GROUP 54A,

Chassis Electrical

− Battery − On-vehicle Service −

Battery Test

P.54A-9

YES : Go to Step 2.
NO : Charge or replace the battery.

CHARGING SYSTEM

TSB Revision

ENGINE ELECTRICAL

16-4

STEP 2.
Q: Is the generator drive belt in good condition? (Refer to

GROUP 00, General

− Maintenance Service − Drive Belts

(For Generator, Power Steering Pump and Air
Conditioning) (Check)

P.00-66

YES : Go to Step 3.
NO : Adjust the belt tension or replace the belt.

STEP 3.
Q: Does the generator malfunction light come on when the

ignition switch is turned on?
YES : Go to Step 4.
NO : Check the ignition switch. (Refer to GROUP 54A,

Chassis Electrical

− Ignition Switch − Ignition

Switch

− Inspection

P.54A-22

Check the generator malfunction light and its related

circuits.

Check the generator. (Refer to Charging System

−

Generator Assembly

− Inspection

P.16-20

STEP 4.
Q: Does the generator malfunction light go out after

starting the engine?
YES : Go to Step 5.
NO : Check the generator (Refer to Charging System

−

Generator Assembly

− Inspection

P.16-20

STEP 5.
Q: Is an oscilloscope available?

YES : Go to Step 6.
NO : Go to Step 7.

STEP 6.
Q: Does the oscilloscope show a normal wave pattern?

(Refer to Charging System

− On-vehicle Service − Wave

Pattern Check Using an Oscilloscope

P.16-11

YES : Go to Step 7.
NO : Check the generator. (Refer to Charging System

−

Generator Assembly

− Inspection

P.16-20

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