ENGINE
3) Alternator
(A) Measurement of adjust voltage
Disconnect the terminal B+ of alternator and connect
ohm - meter with terminal serially. Then connect
load-resistance between ohm - meter and ground
s e r i a l l y. Adjust voltage can be measured between
B+ terminal and ground.
Adjust rotation speed of alternator to reference
speed and adjust alternators reference current.
Measured voltage at this time, it is adjust voltage.
After the voltmeter lead from B+ to D+/61, continuing
load. If the alternator and regulator is normal, voltage
d i fference will be zero. If Voltage difference is about
0.5V or less, regulator is defective generally, if more it
is disorder of alternator. Proceed or replace
a l t e r n a t o r.
(B) Return current
Current must not flow from the battery to the
alternator when the engine stopped and starter
switch is turned “ON”. It means short occured at
plus(+) diode if current flows to alternator.
( C ) Diode test
Test the diode disassembled using 24V DC current
test lamp or ohm-meter connecting forward and
reverse direction.
If (+) terminal of test lamp and anode of diode, (-)
terminal of test lamp and kathode of diode are
connected and the diode is normal, test lamp light
u p - f o r w a r d .
Test lamp will not light up when the polarity is altered.
If it light the diode is damage. Be careful in altering
the polarity is opposite because plus diode and
minus diode is installed opposite position in the
h o u s i n g .
Diode can be tested by ohm-meter.
Resistance of diode is below 10 ohm in forward
connection but it is 50k
Ω
or more in reverse
connection when it is normal.
