16-34 ELECTRICAL SYSTEM
Charging Voltage Inspection
Check the battery condition (see Charging Condition In-
Warm up the engine to obtain actual alternator operating
Remove the front seat (see Front Seat Removal in the
Check that the ignition switch is turned off, and connect
the hand tester to the battery as shown in the table.
Special Tool - Hand Tester: 57001-1394
Battery Charging Voltage
Tester (+) to
25 V DC
Start the engine, and note the voltage readings at various
engine speeds. The readings should show nearly battery
voltage when the engine speed is low, and as the engine
speed rises, the readings should also rise. But they must
be kept under the specified voltage.
Turn off the ignition switch to stop the engine, and discon-
nect the hand tester.
If the charging voltage is kept between the values given in
the table, the charging system is considered to be working
If the output voltage is much higher than the values spec-
ified in the table, the regulator/rectifier is defective or the
regulator/rectifier leads are loose or open.
If the battery voltage does not rise as the engine speed
increases, then the regulator/rectifier is defective or the
alternator output is insufficient for the loads. Check the
alternator and regulator/rectifier to determine which part
There are three types of alternator failures: short, open
(lead burned out), or loss in rotor magnetism. A short or
open in one of the stator coil lead 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 leav-
ing it near an electromagnetic field, or just by aging, will re-
sult in low output.
To check the alternator output voltage, do the following
Remove the front exhaust pipe cover (see Exhaust Pipe
Removal in the Engine Top End chapter).
Disconnect the crankshaft sensor lead connector [A] tem-
Remove the alternator lead connectors [B] to upper side
from the bracket.
at 5 000 rpm
Tester (–) to
14.0 ∼ 15.0 V