2004 ISUZU TF SERIES charging

STARTING AND CHARGING SYSTEM 6D3-9



Generator Power
1. Adjust load resistor, if the required load currents are not
attained.
2. The shape of the voltage curves on oscilloscope curve
should be regular.
3. Test value: 5 to 7A.
4. If the required minimum current intensity is not attained, o
r
if the oscilloscope picture shows variations, the alternator
should be overhauled.

Regulated Voltage Circuit Diagram


Legend
1 Battery
2 Ignition Lock
3 Charge Telltale
4 Resistor, for attainment of load current with the battery set in
series
5 Voltmeter
6 Ammeter
7 Generator




Installation
1. Install generator assembly and bring generator assembly to
the position to be installed.
2. Install generator assembly and tighten to the specified
torque.
Torque:
Long bolt: 35 N




m (3.6 kgf




m)
Short bolt: 20 N





m (2.0 kgf





m)
3. Connect wiring harness connector.
4. Move drive belt tensioner to loose side using a wrench, then
install drive belt to normal position.
5. Reconnect battery ground cable.

6D3-10 STARTING AND CHARGING SYSTEM
The generator has four external connections; the "B+" lead to
battery positive, "L" lead to the warning lamp circuit(max. 2
watts), "S" lead to battery positive terminal for battery sensing
and an earth connection.

Explanation of type inscripiton
Example:KC-A--> 14V 50-90A.

K = Code for Stator OD(126mm OD).
C = Compact Generator.
A = Ausland (countries other than Germany)
> = Direction of rotation(clockwise).
14V = Generator Operating Voltage.
50A = Stabilised output at 25 C at 1800 RPM./13.5
Volts.
90A = Stabilised output at 25 C at 1800 RPM./13.5
Volts.

Generator Connetions.
B+ : Battery Main Connection (battery positive)
S : Battery Sense Connection(battery positive)
L : Waring lamp(via warning lamp to Ignition switch)


BATT.SENSE
REGULATOR ASSEMBLYHYBR10ALTERNATOR ASSEMBLY
12V BATT.1GN.SW.
300a* WARN.LAMP
1.2 WATT
L S8+SUPPRESSOR
CAPACITOR
0.5

f
NOTE: * RESISTOR IS RECOMMENDED TO
ENSURE THAT THE GENERATOR
REMAINS FUNCTIONAL IN CASE OF
WARNING LAMP FAILURE

STARTING AND CHARGING SYSTEM 6D3-11
Warning
Do not reverse S and L connections as this will destroy the
warning lamp circuit of the regulator.
Ensure good electrical contact beween generator earth and
battery negative,

Operation
With the Iginiton switch turnded "ON", current is supplied via
the warning lamp to the "L" terminal of the regulator. Base
current is fed to T15 causing it to turn on, current then flows
from B+ through the rotor winding via the regulator brushes
and the collector emitter junction of T15 to earth completing
the circuit. The current in the rotor causes a magnetic field
between adjacent poles to be created, this field is rotated and
cuts the windings of the stator at right angles inducing a
voltage into them.
As the speed is increased this induced voltage increases and
results in curent being rectified in the 3 phase diode bridge and
supplied as DC to the B+ output and hence to the battery.
When the voltage at the B+ terminal of the battery reaches
around 14.2 volts, this voltage is monitored by the "S" lead and
turns the regulator Hybrid base current to T15 OFF removing
rotor current, resulting in a decrease in output voltage to below
the regulating voltage, T15 base current turns ON and the
whole cycle is repeated very rapidly.
D38 protects T15 and the regulator against the back voltage
developed across the rotor winding when T15 turns OFF.
The new generated EP regulators incorporate current limiting
in the warning lamp circuit.

Backup Regulation
The EP regulator will limit the output voltage to a safe level
should either the main B+ cable or the battery sense wire
become decoupled, the output voltage will be slightly above the
normal setting(1-3 volts).

Start up phase
When the Iginition switch is turned on and the engine is not
running, the current to the rotor is reduced by switching it on
and off at a 50% duty cycle, the frequency is approximately 4
KHz and may be audible at times.
This is quite normal, once the engine is started normal
regulation commences.

Warning lamp failure
Should the warning lamp fail, the generator will self excite by
deriving a small current from the phase connecion allowing the
voltage to build up to regulating level.
Note: no filed current will flow when the engine is cranking.

6D3-12 STARTING AND CHARGING SYSTEM
Diagnosis
The EP regulator incorporates diagnostics which will illuminate
the warning lamp as a result of fault conditions in the generator
and external circuitry.

These conditions include:
1.
An open circuit in the regulator battery sensing wire (S
Terninal)
2. An open circuit or excessive voltage drop in the B+ cable.
3. An open circuit in the generator phase connection.
4. Overcharging of the battery.
5. Regulator output stage short circuit.
6. Open circuit rotor.

The regulator compares the voltage at B+ with the voltage at
the "S" terminal connceted to battery positive. If the voltage
differential exceeds a predetermined threshold, the regulator
will operate in backup mode to limit the output voltage to a safe
level. The warning lamp; will remain illuminated as along as
these conditions prevail.
Sources of high resistance which will trigger the warning lamp
are:

a. Poor contact in wiring harness connectors.
b. Poor contact between rectifier and regulator.
c. High resistance in fusible link assembly.

Caution:
When bench testing the generator it is important that the
warning lamp wattage of 2 watts is not exceeded.
Reversal of the "S" and "L" on the regulator will damage
the regulator.
The correct plug for the regulator is a 9 122 067 011 for the
Bosch tye and for the Shinagawa connector the number is
X02FW.

See appendix 1 for daignostic matrix.
Before testing or disassembling the generator please observe
the following points.

1. When testing the diodes with AC type testers the RMS.
Vlotage output must not exceed 12.0 volts, it is
recommended that the stator should be disconnected
during this test.
2. Where zener power diodes are used, the breakdown
voltage should be tested to ensure all diodes have the
same zener voltage.
3. Insulation tests on the rotor and stator should use a voltage
not exceeding 110v for a series test lamp. The rectifie
r
must be disconnected from the stator prior to testing.
4. When carrying out repairs to the charging system always
disconnected the battery negative first, and reconnect i
t
last.

STARTING AND CHARGING SYSTEM 6D3-13

5. During current output tests please make sure that the
ammeter is securely connceted into the charge circuit.
6. Some battery powered timing lights can produce high
transient voltages when connected or disconnected. Onl
y
disconnect or connect timing lights when the engine is
switched off.
7. Make sure the warning lamp circuit is functioning normall
y
before commencing tests.
8. Battery isolation switches must only be operated when the
engine is stopped.
9. To protect the charging system when using 240 vol
t
chargers it is recommeneded that the battery is
disconnected whilst charging.
10. Due to the very low resistance value of the stator winding i
t
may not be possible to obtain accurate readings withou
t
special equipment.
11. 12 volts must never be connected to the "L" terminal of the
regulator as this will damage the lamp driver circuit.
12. No loads apart from the warning lamp can be connected to
the "L" termainal. The "W" terminal is provided for this
purpose.

Disassembly
1. Mark the relative positions of the end housings in relation to
the stator assembly to aid reassembly. Use a permanen
t
marking pen do not use centre punched as this can cause
misalignmnet of the housings.
2. Remove the EP regulator from the slipring end housing b
y
removing the two screws. Tilt the regulator slightly from the
plug connection until the regulator clears the housing, then
lift clear.
3. Remove the four through bolts.
4. Carefully remove the stator assembly along with the slipring
end housing taking care not to put strain on the stator wires.
5. To disconnect the stator from the rectifier assembly, grasp
the stator wires close to the wire loop with a pair of long
nosed pliers, heat the joint with a soldering iron, when the
point becomes plastic apply a slight twisting motion to the
wires, then pull upwards to release the wires. Remove the
stator.
This procedure opens the wire loop to release the stato
r
connections easily.
6. To remove the rectifier remove the three retaining scre
w
and the B+ terminal nut and washers.

Note: the B+ bolt and the positive heatsink retaining screw are
fitted with mica insulating washers.
These must be discarded and replaced with new washers and
heatsink compound.

6D3-14 STARTING AND CHARGING SYSTEM

7. To remove the pulley, mount an 8mm Allen key in the vice
with the short end upwards, place a 24mm ring spanner on
the puley nut, position the internal hexagon of the roto
r
shaft onto the Allen ken, loosen the nut and remove the
pulley.

Note: the pulley has an integral boss which locks up against
the bearing,
therefore no thrust collar is provided.
8. Removing the rotor assembly. Remove the four retaining
screws from the drive end housing, withdraw the roto
r
complete with the bearing.

Note: the rotor must not be pressed from the drive end housing
using a press as the bearing retaining plate and drive end
housing will be damaged or distorted. Parts removed in this
way must be replaced if the integrity of the generator is to be
maintained.
9. Remove the drive end bearing from the rotor shaft using a
chuck type puler, take care not to distort the fan assembl
y
during this process.
10. Remove the slipring end bearing using the same meghod
as in 9.

Clean
Thoroughly clean all components except the rotor and stator
with an approved cleaning agent. Ensure that all traced of oil
and dirt are removed. If an abrasive cleaner is used to remove
scale and paint from the housings take care not to abrade the
bearing and mounting spigot surfaces. The rotor and stator
must be cleaned with compressed air only, the use of solvents
could cause damage to the insulating materials.

Inspection
1. Rectifier assembly
The following test equipment is required.
The recitifier assembly is not repairable and must be replaced
if a faulty diode is detected during inspection.

(a)
Adiode tester where the DC output at the test probes does
not exceed 14 volts or in the case of AC testers 12 volts
RMS. This is to ensue that when inspection rectifiers fitted
with zener power diodes the forward and reverse checks
are completer and are not masked by the diode turning on
due to the zener breakdown voltage.
(b) A zenere diode tester with a DC output in excess of 30
volts, the tester should also incorporate internal curren
t
limiting set to 5 Ma. to prevent high currents during
inspection.
(c) Diodes can be destroyed during service due to high
temperature and overload, open circuits are usually a resul
t
of excessive voltage.

STARTING AND CHARGING SYSTEM 6D3-15
Positive heatsink 8 diode 6 diode
H
G
Negative heatsink C
B
A
StarpointFEB+Bolt D Diode connections
Stator connection


1.1 Power Diodes.
Apply the negative test probe of the diode tester or a
multimeter with a diode test feature to the positive heatsink
and the positive probe alternatevely to A,B,C, a low resistance
reading, or the forward voltage drop across the diode shoud be
obtained. Reverse the test probes, a high resistance reading or
a higher reverse voltage should be obtained.

Now connect the positive test probe to the negative heatsink
and the negative alternatively to D,E,F, a low resistance or
forward voltage drop across the diode should be obtained.
Reverse the test probes, a high resistance reading or a higher
reverse voltage should be obtained.

For 8 diode rectifier plates tests for G and H should be
included. When the reverse voltage test is done the applied
voltage should be less than 14 volts DC or 12 volts RMS for
AC testers.



1.2 Zener Diode
The basic tests in 1.1 should be undertaken first before the
diode zener voltage is tested. Diodes are grouped together
according to their zener voltag i.e. all diodes within a rectifier
must have the same zener voltage.

Connect the test probes as for the reverese test listed above
i.e. reverse biased apply the test voltage form the zener diode
tester (current limited to 5ma) and read to zener breakdown
voltage this should be a steady reading and not increase with
increased voltage from the tester.

6D3-16 STARTING AND CHARGING SYSTEM




Readings for Zener diode groups 011 to 042

Zener voltage at
5Ma.Positive
diodeNegative
diodeFordward
current Rating
17.8v-19.2v 011 012 25A
18.8v-20.2v 013 014 25A
19.8v-21.2v 015 016 25A
20.8v-22.2v 017 018 25A
21.8v-23.2v 019 020 25A
22.8v-24.2v 021 022 25A
17.8v-19.2v 031 032 35A
18.8v-20.2v 033 034 35A
19.8v-21.2v 035 036 35A
20.8v-22.2v 037 038 35A
21.8v-23.2v 039 040 35A
22.8v-24.2v 041 042 35A

Note: Diode number is stamped on the rear of the diode.



























2. Stator
Inspect the stator insulation resistance to ground with an
insuation tester or a series test lamp up to 110 volts.
The insulation resistance must be greater than 1 megohm.
The winding reisistance is measured between phases using a
low reading ohmmeter designed for this purpose, the values
are given at the rear of this instruction.

3. Rotor
Inspect the rotor for insulation resistance to ground using an
insulation tester or a series test lamp up to 110 volts.
The insulation resistance must be grater than 1 megohm.
Measure the rotor resistance between the sliprings using an
ohmmeter or apply 12 volts across the sliprings and measure
the rotor current flow, then divide 12 by the measured current,
the results is the rotor resistance in ohms. values are given at
the rear of this instruction.

If the sliprings are worn or out of round they must be re-
machined to a minimum diameter or 26.7 mm and should have
a runout not exceeding 0.060mm. If the slipring is below these
limits it must be replaced with a new one.

Warning; extreme care must be exercised when machining
the slipring as it is possible for the turning tool to foul the