Mitsubishi FUSO FH 1997, Service Manual

Page: 23 / 200

00-14
Inspection procedures for blown fuses
Remove fuse B and measure resistance between the loaded side of
the fuse and ground.
Turn on all circuit switches (connected to the fuse). If the resistance
value reading is approximately 0
Ω
, a short has occurred between the
switch and the loaded point. A value of other than zero may indicate
that the fuse was blown by a temporary short but the short is no longer
present.
The major causes of a short circuit are as follows:
• Harness stuck onto the vehicle body.
• Harness sheath damaged by friction or heat.
• Water in connectors or circuits.
• Mistakes (accidental short circuits)
A : Battery
B : Fuse
C : Loaded switch
D : Load
E : Short circuit
02596
+
_
_
+
0
Ω
A
E
B
C
D
• While the engine is running, do not remove the battery terminals. If
the battery terminals are removed at that time, a surge voltage is
generated and the diode or regulator might be weakened.
• Do not use a high-voltage tester such as a megger for inspection.
If a high-voltage tester is used, the diode or regulator might be
destroyed.
04747
02371
Precautions for handling alternator
When servicing the alternator, pay attention to the following :
• Do not connect the alternator with battery polarities reversed.
If the alternator is connected with reversed polarities, a large cur-
rent flow from the battery to the alternator occurs, and the diode or
regulator might be damaged.
04746
PRECAUTIONS FOR MAINTENANCE OPERATION