ENGINE-ELECTRICAL SYSTEM
3-3-10
Alternator Inspection
There are three types of alternator failures: short, open,
or loss in rotor magnetism. A short or open in one of the
coil wires will result in either a low output, or no output
at all. A loss in rotor magnetism, which may be caused
by dropping or hitting the alternator, by leaving it near an
electromagnetic field, or just by aging, will result in low
output.
◆
To check the alternator output voltage, perform the
following procedures.
◆
Disconnect the alternator connector
【
A
】
.
◆
Connect a hand tester as shown in the table.
◆
Start the engine.
◆
Run it at the rpm given in the table.
◆
Note the voltage readings (total 3 measurements).
Alternator Output Voltage
Alternator Output Voltage
Tester
Range
Connections
Reading
@3000rpm
Tester (+) to Tester (–) to
250V AC
One yellow
lead
Another
yellow lead
36~54 V
If the output voltage is within the values in the table, the
alternator is operating correctly, and the regulator/rectifi er
is damaged. A much lower reading indicates that
the alternator is defective.
◆
Check the stator coil resistance as follows:
◆
Stop the engine.
◆
Disconnect the alternator connector.
◆
Connect a hand tester as shown in the table.
◆
Note the readings (total 3 measurement).
A