TCM FB-8 Series, Service Manual

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2. ELECTRICAL PARTS AND PROCEDURES FOR CHECKING
2.2.7 FUSE (F1)
If too large a current flows in the main circuit, the
fuse (F1) will blow to prevent the controller from being
damaged or catching fire.
Applicable truck model Symbol Type
1-ton and 3-ton class trucks F1 96LFB-400
2-ton class trucks F1 96LFB-500
Checking procedure
①
Set the multimeter to measure voltage and connect the negative probe to the negative cable
connection terminal on the controller.
②
Connect the positive probe to the F1 fuse. Measure the voltage and determine whether the fuse is
defective or not.
1 to 1.8-ton trucks
Measurement point Voltage Judgment
Cable-side terminal Battery voltage Good
Contactor-side terminal
Battery voltage Good
0 (V) Defective (Replace the fuse with a new one)
2- to 3.5-ton trucks
Measurement point Voltage Judgment
Cable-side terminal Battery voltage Good
Contactor-side terminal
Battery voltage Good
0 (V) Defective (Replace the fuse with a new one)
Note
If the fuse is blown, find the cause of the blown fuse (overloading, shorting or grounding) and take
the necessary repair measures before replacing the fuse.
2.2.8 ACCELERATOR PEDAL
The accelerator pedal controls the traveling speed. It outputs a
signal according to the angle at which the pedal is pressed.
Two accelerator potentiometers are installed to allow a broken
signal line to be detected.
Checking procedure
①
Turn on the key switch in the truck. Lift the front wheels off
the ground.
②
Press and hold the MODE button on the control panel for at
least 3 seconds.
③
Press and hold the SPE button on the control panel for at least
3 seconds.
A
(Accelerator 1
potentiometer
output voltage)
B
(Accelerator 2
potentiometer
output voltage)
Accelerator pedal released 1.0 V 0.5 V
Accelerator pedal pressed fully 3.92 V 1.96 V
Note: The voltage at B is always supposed to be half of the voltage at A.
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+
-
+
LY 93
LW 187 BG 186
LG 92 WR 185 LB 184
CN2D-32
ACCEL1 POT. ACCEL2 POT.
CN2D-20 CN2D-8 CN2D-33 CN2D-21 CN2D-9
F1
コンタクタ側
ケーブル側
Contact side
Cable side