Suzuki Grand Vitara JB416 / JB420 / JB419. Manual — part 207

1J-18 Charging System: For Diesel Engine Model

Generator Description

S6JB0A1A21002

The generator is a small and high performance type with an IC regulator incorporated. The internal components are
connected electrically as shown in the following figure.
The generator features are as follows:
• Solid state regulator is mounted inside the generator.
• All regulator components are enclosed into a solid mold.
• This unit along with the brush holder assembly is attached to the rear housing.
• The IC regulator uses integrated circuits and controls the voltage produced by the generator, and the voltage setting

cannot be adjusted.

• The generator rotor bearings contain enough grease to eliminate the need for periodic lubrication. Two brushes

carry current through the two slip rings to the field coil mounted on the rotor, and under normal conditions will
provide long period of attention-free service.

• The stator windings are assembled on the inside of a laminated core that forms part of the generator frame.

I5JB0B1A0001-05

1. Generator with regulator assembly

3. Stator coil

5. Field coil (rotor coil)

7. Main switch

9. Load

2. I.C. regulator

4. Diode

6. Charge indicator light

8. Battery

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1. Pulley

5. Field coil

9. Drive end frame

L: Lamp terminal

2. Rotor fan

6. Regulator

B: Generator output (Battery terminal)

IG: Ignition terminal

3. Stator coil

7. Brush

E: Ground

C: Dummy

4. Stator core

8. Rear end frame

F: Field coil terminal

Charging System: For Diesel Engine Model 1J-19

Diagnostic Information and Procedures

Battery Inspection

S6JB0A1A24001

Common Causes of Failure
A battery is not designed to last indefinitely; however,
with proper care, it will provide many years of service. If
the battery performs satisfactorily during test but fails to
operate properly for no apparent reason, the following
are some factors that may point to the cause of trouble:
• Accessories leave on overnight or for an extended

period without the generator operating.

• Slow average driving speeds for short periods.
• Electrical load exceeding generator output particularly

with addition of aftermarket equipment.

• Defects in charging system such as high resistance,

slipping drive belt, loose generator output terminal,
faulty generator or voltage regulator. Refer to
“Generator Symptom Diagnosis: For Diesel Engine
Model”.

• Battery abuse, including failure to keep battery cable

terminals clean and tight or loose battery hold down.

• Mechanical problems in electrical system such as

shorted or pinched wires.

Battery Test
Visual inspection
Check for obvious damage, such as cracked or broken
case or cover, that could permit loss of electrolyte.
If obvious damage is noted, replace battery. Determine
cause of damage and correct as needed.

Hydrometer test
The direct method of checking the battery for state of
charge is to carry out a high rate discharge test, which
involves a special precise voltmeter and an expensive
instrument used in the service shops, but not
recommendable to the user of the vehicle.
At 20

°C of battery temperature (electrolyte

temperature):
• The battery is in FULLY CHARGED STATE if the

electrolyte S.G. is 1.280.

• The battery is in HALF CHARGED STATE if the S.G.

is 1.220.

• The battery is in NEARLY DISCHARGED STATE if

the S.G. is 1.150 and is in danger of freezing.

As the S.G. varies with the temperature, if battery
temperature is not at 20

°C (68 °F), you have to correct

your S.G. reading (taken with your hydrometer) to the
value at 20

°C (68 °F) and apply the corrected S.G. value

to the three-point guide stated value.
For the manner of correction, refer to the graph showing
the relation between S.G. value and temperature.

How to use the temperature-corrected state-of-
charge graph
Suppose your S.G. reading is 1.28 and the battery
temperature is –5

°C (23 °F). Locate the intersection of

the –5

°C line and the 1.28 S.G. line.

The intersection is within the “A” zone (shaded area in
the graph) and that means CHARGED STATE.
To know how much the battery is charged, draw a line
parallel to the zone demarcation line and extend it to the
right till it meets with the percentage scale. In the present
example, the line meets at about 85% point on the
percentage scale.Therefore, the battery is charged up to
the 85% level.

[a]: Gravity
[b]: Temperature

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1J-20 Charging System: For Diesel Engine Model

Generator Symptom Diagnosis

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CAUTION

• Do not connect any load between “L” and

“E” terminals.

• When connecting charger or booster

battery to vehicle battery, refer to “Jump
Starting in Case of Emergency: For Diesel
Engine Model”.

Trouble in charging system will show up as one or more
of the following conditions:

1) Faulty indicator lamp operation.
2) An undercharged battery as evidenced by slow

cranking.

3) An overcharged battery as evidenced by excessive

spewing of electrolyte from vents.

Noise from generator may be caused by loose drive
pulley, loose mounting bolts, worn or dirty bearings,
defective diode, or defective stator.

Charging Indicator Lamp Operation

Generator Test (Undercharged Battery Check)

S6JB0A1A24003

This condition, as evidenced by slow cranking or low
specific gravity can be caused by one or more of the
following conditions even though indicator lamp may be
operating normal. The following procedure also applies
to cars with voltmeter and ammeter.
• Make sure that undercharged condition has not been

caused by accessories left on for extended period of
time.

• Check drive belt for proper tension.
• If battery defect is suspected, refer to “Battery

Description: For Diesel Engine Model”.

• Inspect wiring for defects. Check all connections for

tightness and cleanliness, battery cable connections
at battery, starting motor and ignition ground cable.

No-Load Check

1) Connect voltmeter and ammeter as shown in figure.

NOTE
Use fully charged battery.

B: Generator output (Battery terminal)

L: Lamp terminal

E: Ground

IG: Ignition terminal

F: Field coil terminal

C: Dummy

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Condition

Possible cause

Correction / Reference Item

Charge light does not
light with ignition ON and
engine off

Fuse blown

Replace fuse and check for short circuit.

Indicator lamp (LED) faulty

Replace combination meter.

Wiring connection loose

Tighten loose connection.

IC regulator or field coil faulty

Check generator.

Poor contact between brush and slip
ring

Repair or replace.

Charge light does not go
out with engine running
(battery requires frequent
recharging)

Drive belt loose or worn

Replace drive belt.

IC regulator or generator faulty

Check charging system.

Wiring faulty

Repair wiring.

1. Generator
2. Ammeter (between generator “B” terminal and battery (+) terminal)
3. Voltmeter (between generator “B” terminal and ground)
4. Battery
5. Load
6. Switch

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Charging System: For Diesel Engine Model 1J-21

2) Run engine from idling up to 5,000 rpm with all

accessories turned off and read meters.
If voltage is higher than standard value, check
ground of brushes.
If brushes are not grounded, replace coil assembly.
If voltage is lower than standard value, proceed to
the following check.

Specification for undercharged battery (No-load
check)
Current: 10 A
Voltage: 14.2 – 14.8 V (at 25

°C, 77 °F)

NOTE
Consideration should be taken that voltage
will differ somewhat with regulator case
temperature as shown in figure.

3) Remove generator rear end cover.
4) Ground “F” terminal and start engine, then measure

voltage at “B” terminal as shown in figure.
• Voltage is higher than standard value. It is

considered that generator itself is good but IC
regulator has been damaged, replace coil
assembly.

• Voltage is lower than standard value. It is

considered that generator itself has problem,
check the generator.

Generator Test (Overcharged Battery Check)

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1) To determine battery condition, refer to “Battery

Description: For Diesel Engine Model”.

2) If obvious overcharged condition exists as evidenced

by excessive spewing of electrolyte, measure
generator “B” terminal voltage at engine 5,000 rpm.

3) If measured voltage is higher than upper limit value,

disassemble generator.

4) Check ground of brushes. If brushes are not

grounded, replace coil assembly. Then check field
coil for grounds and shorts.

[A]: Regulated voltage (V)
[B]: Heatsink temperature

16.0

15.5

14.3

15.2

14.8

14.2

13.3

14.6

15.0

14.5

14.0

13.5

13.0

-30

[A]

[B]

120 (˚C)

248 (˚F)

(V)

I6JB0A1A2001-01

"B"

"F"

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