ALTERNATOR
11-6
3TNV88F Service Manual
Alternator Troubleshooting
ALTERNATOR TROUBLESHOOTING
T
urn key switch ON.
Does battery indicator
turn ON?
At idle, does battery
indicator turn OFF?
Does battery indicator
come ON?
Ground drive machine side
L
terminal. Does battery
indicator turn on?
Does battery indicator
come ON?
Start Engine.
ON
OFF
OFF
OFF
OFF
ON
ON
OFF
Battery indicator ON.
Disconnect harness L
terminal
and IG terminal at alternator
Increase engine speed to
1500 rpm.
T
urn light switch ON.
With engine running at 1500
rpm, measure voltage at
battery
.
Notes:
1. Use a fully charged battery
2. DC voltmeter: 0 to 30 V
, 0.5 class
3.
The check method is also applicable to the bench test
With engine idling,
measure voltage at L
terminal and at battery
.
With engine idling,
turn light switch ON.
Replace the battery indicator
.
Battery indicator is available from
driven machine manufacturer
.
Battery indicator flashes.
Battery voltage
is between 13
and 15 volts.
Battery voltage greater
than 15.5 volts.
Battery voltage minus
L
terminal voltage is
greater than 0.5 volt.
Battery voltage minus
L
terminal voltage is
less than 0.5 volt.
Battery indicator
is dim.
Battery indicator
is dim.
Inspect rotor assembly and
brushes.
Excessive voltage drop between
BA
T
and batt ( + side) terminal.
Check condition of L
terminal.
Inspect diode negative (-) side.
Replace regulator
.
Inspect auxiliary diode.
Not abnormal.
Inspect or replace V
-belt.
Inspect alternator
.
Inspect diode positive (+) side.
3TNV88F_SVM_A4.book 6 ページ 2012年7月26日 木曜日 午後6時4分