ISUZU TROOPER 1998 Service Repair Manual

CHARGING SYSTEM 6D3 Ð 5
UNIT REPAIR
Disassembly Steps
1. Vacuum pump
2. Through bolt
3. Pulley nut
4. Pulley
5. Fan
6. Rotor
7. Spacer
8. Front cover assembly
9. Bearing retainer
10. Front bearing11. Rear bearing
12. Terminal bolt and nut
13. Rear cover
14. Stator
15. Diode
16. IC regulator assembly
17. Brush holder
Reassembly Steps
To reassemble, follow the disassembly steps in the
reverse order.

6D3 Ð 6 CHARGING SYSTEM
DISASSEMBLY
1. Vaccum Pump
¥Dram fluid from discharged port.
¥Remove the vacuum pump fixing bolts. Hold the
center plate and remove the vacuum pump
horizontally in direction in line with the rotor
shaft.
2. Through Bolt
3. Pulley Nut
¥ Cover the vice with copper plates, clamp the rotor
with vice, and remove the nut.
4. Pulley
5. Fan
6. Rotor
7. Spacer
8. Front Cover Assembly
9. Bearing Retainer
10. Front Bearing
11. Rear Bearing
12. Terminal Bolt and Nut
13. Rear Cover
¥ Remove the nuts fixing the B terminal and diode
holder.
Separate the stator and rear cover.
Note the position of insulation washers to ensure
reassembly into original position.
14. Stator
15. Diode
¥ Separate the diodes from the stator by melting
away solder on stator coil and diode.
When melting solder, hold the lead wire with
longnose pliers to prevent heat from being
transferred to the diodes.
16. IC Regulator
¥¥ Separate the IC regulator from the diode by
melting away solder on IC regulator holder plate
and removing the nut.

CHARGING SYSTEM 6D3 Ð 7
17. Brush Holder Assembly
¥ Remove the serrated bolts and melt away solder on
IC regulator.
¥ Do not remove the serrated bolts unless the
replacement of brush or condenser.
To install, follow the removal steps in the reverse
order.
INSPECTION AND REPAIR
Repair or replace necessary parts if extreme wear or
damage is found during inspection.
ROTOR ASSEMBLY
1. Check the rotor slip ring surfaces for contamination and
roughness. If rough, polish with #500-600 sandpaper.
2. Measure the slip ring diameter, and replace if it exceeds
the limit.
3. Check for continuity between slip reings, and replace if
there is no continuity.
4. Check for continuity between slip ring and rotor core or
slip ring and rotor shaft.
In case of continuity, replace the rotor assembly.
STATOR COIL
1. Check for continuity between respective phases.
In case of no continuity, replace the stator.
2. Check for continuity across one of the stator coils and
stator core. If a continuity exists, replace the coil.
34.6(1.36) 33.6(1.32)mm (in)
Standard Limit

6D3 Ð 8 CHARGING SYSTEM
DIODE
1. Check for continuity across the terminal (example:
across BAT and U). If a continuity exists, the diode is
in satisfactory condition. If no continuity exists the
diode is defective.
2. Make a test with the polarities reversed. If no
continuity exists, the diode is in satisfactory
condition. If a continuity exists at any point, the
diode is defective and should be replaced.
Auxiliary diodes are not provided with the terminal
and continuity test should be made across the
terminals of the conventional diodes.
BRUSH
Measure length of brushes.
Brush length (L)
Across terminals BAT (Positive side (+) diodes)
Tester pin
Positive side
Negative sidePositive side
ContinuityNegative side
No continuity
U.V.W.
Across terminals BAT (Positive side (+) diodes)
Tester pin
Positive side
Negative sidePositive side
ContinuityNegative side
No continuity
U.V.W.
20(0.7) 6 (0.24)mm(in)
Standard Limit
Brushes are provided with a line which indicates the
limit of usage.

CHARGING SYSTEM 6D3 Ð 9
IC REGULATOR
Measureing instruments is necessary.
Take the following measurements with the
instruments connected as shown in the illustration.
¥ V1 Voltage at BAT1
¥ V2 Voltage across FÐE
¥ Take measurement with ÔSÕ terminal disconnected.
¥ V3 Measure the voltage at BAT1 Ð BAT2.
¥ Measurement the voltage across the EÐF while
varying resistance gradually from zero using variable
resistor.
Then check that voltage increases from 2V to 10 Ð 13.
If increase in voltage is interrupted at any point,
replace the regulator.
¥ V4 Measure the voltage across the intermediate tap
on variable resistor and ÔEÕ terminal without actuating
the variable resistor.
If measured value deviates from the standard, replace the
regualator.
Check the following with the instrument connected as
illustrated.
Measure the voltage across the teminals B and E by
gradually increasing voltage with variable resistor RV.
Check to see if voltage increases from lower than 2V to
range from 10 to 13 volts.
If the voltage does not vary, the regulator is defective and
should be replaced.
Check the voltage across the intermediate tap of the
variable resistor and terminal E without actuating the
variable resistor.
If measured voltage deviates from the standard value,
replace the regulator.
Standard 10 – 13
V
Standard Limit
2 or less
2 or more
V
Standard 20 – 26V
Standard voltage at 20°C (68°F) 14.0 – 14.6
V
Standard voltage at 20°C (68°F) 14.5 – 16.6
V

6D3 Ð 10 CHARGING SYSTEM
VACUUM PUMP
Visual check
¥ Inspect the following parts for wear, damage or other
abnormal conditions.
Standard60.0 – 60.1
(2.362 – 2.366)mm (in)
Vane
Measure the length of vanes
Standard 14.2– 15.2(0.559–0.598)mm (in)
Check valve
1. Apply a light pressure onto the ÓBÓ side of valve with
a screw driver and check that valve operates
smoothly.
2. Apply compressed air onto ÓAÓ side of valve and
check if there is air leak.
Housing
¥ Measure the inside diameter of housing and place if it
exceed the standard.
Reassembly of vacuum pump
1. Position the rotor, with the serrated boss turned up,
on the center plate and housing.
Align the holes in center plate and rotor.
2. Install vanes into slits in rotor.
The vanes should be installed with chamfered side
turned outward.
3. Install the O-ring and center plate
Disassembly of Vacuum pump
¥ For the center plate, rotor and vane in the mentioned.

CHARGING SYSTEM 6D3 Ð 11
REASSEMBLY
17. Brush Holder
16. IC Regulator Assembly
¥ Hold the brush in the holder as shown in the
illustration and solder the lead wire.
¥ Put the IC regulator on the brush holder and
press the bolt.
Bushing and connecting plate must be installed
when pressing the bolt.
15. Diode
¥ Connect the terminals by fixing the rivet at À
and soldering the terminal at Á .
14. Stator
¥ When connecting stator coil leads and diode
leads using solder, use long-nose pliers and
finish the work as quickly as possible to prevent
the heat from being transferred to the diodes.
13. Rear Cover
12. Terminal Bolt and Nut
11. Rear Bearing
10. Front Bearing
9. Bearing Retainer
8. Front Cover Assembly
7. Spacer
6. Rotor
5. Fan
4. Pulley
3. Pulley Nut
¥ Cover vice with copper plates, clamp the rotor
with the vice, and tighten nut to the specified
torque.
2. Through Bolt
¥ Place guide bar through the holes in front cover
and rear cover flange for alignment, then install
the through bolts.
1. Vacuum Pump
¥ Install and mount the housing to the generator
using 3 bolts.
¥ Pour engine oil (5 cc or so) in through the filler
port, then check that generator pulley can be
turned smoothly with hand.

6D3 Ð 12 CHARGING SYSTEM
52 (5.3 / 38)N·m (Kg·m/lb·ft)
7 (0.7 / 61)N·m (Kg·m/lb·in)
7 (0.7 / 61)N·m (Kg·m/lb·in)

QOS III PREHEATING SYSTEM 6D6 Ð 1
PAGE
General Description ........................................................................................................ 6D6- 1
System Diagram .............................................................................................................. 6D6- 2
GENERAL DESCRIPTION
QOS III preheating system features a quick-on glow
plug with thermometer control of the glowing time
and the afterglow time function.
The system consists of a controller, indicator lamp,
thermosensor, vehicle speedsensor, dropping
resistor, relay (2 pcs), and temperature self-control
type glow plug (4 pcs).With the employment of the thermosensor, the
glow time changes according to the engine coolant
temperature, thus allowing optimum starting
conditions to be obtained.
The afterglow time function is controlled by
thermosensor, vehicle speed sensor, and the
engine runstall sensor (charge relay).
SECTION 6D6
QOSIII PREHEATING SYSTEM
CONTENTS

6D6 Ð 2 QOS III PREHEATING SYSTEM
SYSTEM DIAGRAM
WIRING DIAGRAM
ON
B
ST
Glow relay No.1 Starter SW
Battery
Engine Glow relay No.2
Glow indicator
Charge
relayGlow plug
Thermo
sensor
Controller;
QOS-III
Speed sensorDropping
registor
QOS III Timing Chart
ST
ON
OFF
ON
OFF
ON
OFF
ON
OFF
18Km/h
9km/h
ON
OFF
ON
OFF
ON
OFF Starter SW
Starter SW is turned to
“ST” before indicator light
goes out.Starter SW is turned to
“ST” after indicator light
goes out.Starter SW
is left “ON”
Indicator timer
After glow timer
Charge relay
Indicator light
Relay 1
Relay 2Above
Vehicle speed below
t i t i t i
t a t a
t d t d t d t d
Glow plug
temperature
0t 0t 0t
: Indicator light “ON” time
: Rapid after glow (Delay timer) time
: After glow time
ti
td
ta
(For broken lines,
water temperature
is 70¡C or above)