TM 5-3805-258-24-1
9 5 0 B O P E R A T O R ’ S S T A T I O N
E L E C T R I C A L T R O U B L E S H O O T I NG
PROBLEM C: An Indicator That Must Be OFF, Is ON.
Possible Causes: a. Bad switch (sensor).
b. Bad ground wire to switch (broken wire or bad connec-
tion).
c. Bad control wire to switch (broken wire or bad connec-
tion ).
d. Bad operator panel.
TROUBLESHOOTING
1. Remove the control wire from the switch (sensor) and put it to machine
ground (See TABLE 3). The indicator must turn OFF.
I
T A B L E 3
Control Wire Color
Harnesa Plug Socket
at Switch
Switch
at Operator Panel
YIPU
Hydraulic Oil Temperature
4
LT BL
Coolant Temperature
6
Y/o
I
Transmission Oil Temperature
I
7
GYIP
Low Brake Oil Pressure
2
I
T/O
] Fuel Level
I
14
Indicator Turns OFF
Indicator Stays ON
Either the switch or the ground is bad. Go to Step 2.
There is either an open wire in a harness, or the
operator panel is bad. Go to Step 3.
2. Check for continuity across the switch with an 8S4627 Circuit Tester.
Continuity
No Continuity
If there is continuity across the switch, then the
Replace the switch (sensor).
ground for the switch is bad. Replace the harness or
connect another ground wire to the switch.
3. Check for continuity through harnesses from the switch to the operator panel.
Fasten the control wire for the switch to machine ground. Disconnect the
harness plug from the operator panel and check for continuity at the plug socket
that is for the switch that is grounded (See TABLE 3). Use an 8S4627 Circuit
Tester.
Continuity
No Continuity
Replace the operator panel.
Use the electrical schematic or simplified schematic
to check through each harness between the switch
and the operator panel, until the one with the broken
wire is found. Repair or replace the harness.
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