Komatsu 4D98 Series Shop Manual page 162

10. Alternator
10.2.3 Troubleshooting
Battery over-discharge, charge lamp on or overcharge
Key switch to OFF
Battery open
NG
* voltage measurement -
Battery
VB=lZ-13v
replacement
IClK I
Key switch to ON and
charge lamp on check
I
NG
+ Disconnect the alternator coupler, ground the L terminal of
OK
vehicle side harness. and check lighting of the charge lamp.
OK
NG
I
Check and correct the charge lamp and wiring.
Key switch to START
(engine starting)
Check charge lamp off
Fan belt tension
Battery voltage at an engine
speed of 2500 rpm
VB + 12.5 - 14.7V
OK
I
Electrical load (head lamp) on.
Check charge lamp on or off
OFF
ON
I
Key switch to OFF
Dark current measurement
I<50mA
Recheck by disconnecting
alternator B terminal
_
I<50mA
OK
[OK
I
v
I -
Alternator in normal state
Alternator inspection
lo-16