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 N G
PROBLEM D: Fault Alarm is ON When It Must Be OFF.
Possible Causes: a. Fuel pressure switch is bad (open when there is no pres-
sure).
b. A broken wire that goes to the fuel pressure switch.
c. A short in the harness (wire to the fault alarm is shorted
to a wire with + 24V).
d. Operator panel is bad.
1. Remove the BR wire from the fuel pressure switch and connect it to machine
ground.
Fault Alarm Stops
Fault Alarm Does Not Stop
Fuel pressure switch or ground wire to switch is bad.
Go to Step 3.
Go to Step 2.
2. Remove the B wire from the fuel pressure switch and check for continuity
through the switch with an 8S4627 Circuit Tester.
Continuity
No Continuity
Ground wire is bad. Repair or replace the harness or
I
Replace the fuel pressure switch.
connect a ground wire to the switch.
3. Connect wires to fuel pressure switch again. Disconnect the harness plug
from the operator panel.
Fault Alarm Stops
Fault Alarm Does Not Stop
Go to Step 5.
There is a short in plug or harness between wire to
Socket 10 that sends power to fault alarm and an-
other wire (1, 11 or 16) that has power. Go to Step 4.
4. Use an 8S4627 Circuit Tester to check for a short between Sockets 10 and 1,
10 and 11, and 10 and 16.
Repair or replace the harness.
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