Yanmar 4JH2E Service Manual page 344

Chapter 9 Electrical System
4. Alternator
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4JH
Series
(3) Assembling the rear cover
Insert pins from the outside of the rear cover. Install the
brush on the brush holder. then attach the rear cover.
After assembly, pull out the pins.
(4)
Tightening torques
Positions
Brush holder fixing
Diode fixing
Bearing retainer fixing
Pulley nut tightening
Through-bolt tightening
4·10 Performance test
3rwsn hclCer
Brush
Tightening torque
kg-cm
(ft-lb)
Pin
32-40 (2.31
~
2.89)
32-40 (2.31
~
2.89)
32-40 (2.31
~
2.89)
400-600 (28.93
~
43.40)
32-40 (2.31
~
2.89)
Conduct a performance test on the reassembled AC
generator as follows. The following is the circuit for the
performance test.
Variable resistor
SW,
Charge lamp
T
I
Battery
'
swf _._
.,
~+--<"'W'r'
L-----j~-------1
"./
Printed in Japan
AOAJ029-9002
0.25Q Resistor
Connect when
the batteries
are discharged
9-33
(1) Measuring devices
DC voltme:er 0-15V
or
0-30V, 0.5 Class, 1pc.
DC ammeter
0-100A, 1.0 Class. 1pc.
Variable resistor 0-025Q, 1kW, 1pc.
Lamp
12V, 3W
100Q resistor
3W
025Q resistor 2511/
(2) Measuring the regulating voltage
1) When measuring devices are connected in the
performance test circuit as shown above, the charge
lamp lights.
2)
Close SW, while keeping SW, open and run the AC
generator. When the revolutions of the generator are
gradually raised, the charge lamp goes off.
3) Raise the revolutions of the AC generator, and read the
voltmeter gauge when the revolutions reach about
5,000 rpms.
NOTES: 1. Make sure that the ammeter indication at this
time is Jess than
SA.
If the indication is over
SA, connect the 0.25Q resistor. The voltmeter
indication at this time must be within the
prescribed regulating voltage value.
2.".Raise the AC generator revolutions high to
make sure the regulating voltage does not
fluctuate along with changes in the revolution
speed.
(3)
Precautions for measuring the regulating voltage
1) When measuring the voltage, measure the voltage
between the AC generator BAT terminal, or Battery
+
tenminal, and AC generator E-terminal.
2)
Use a fully charged battery.
3)
Measure the voltage quickly.
4) Keep SW, open for measurement.