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 A: All Indicators, Master Fault Light And Fault Alarm OFF.
Possible Cause: System voltage is over 36 volts
TROUBLESHOOTING
1. Check system voltage with a voltmeter.
Voltage Greater Than 36V
Voltage Less Than 36V
Repair or replace the alternator and regulator.
Do TEST I again.
PROBLEM B: Fault Alarm Does NOT Turn ON.
Possible Causes: a. Fuel pressure switch that controls fault alarm is bad.
b. Wire from operator panel to fuel pressure switch is
grounded.
c. Fault Alarm is bad.
d. Wire from operator panel to fault alarm has an open or a
ground.
e. Operator panel is bad.
The fuel pressure switch controls the operation of the fault alarm. When the
engine is in operation and the fuel pressure is high enough, the fuel pressure
switch opens. When the fuel pressure switch is open, the fault alarm can be
activated if the test switch is in the TEST position or if one of the indicators is
ON that calls for the fault alarm to also be ON.
TROUBLESHOOTING
1. Disconnect the BR wire from the fuel pressure switch. The fault alarm must
be activated (same as an open switch) with the test switch in the TEST position.
Fault Alarm Turns ON
Fault Alarm Does NOT Turn ON
Replace the fuel pressure switch.
Go to Step 2.
2. Disconnect the harness plug from the operator panel and check for contin-
uity between BR wire that connects to the fuel pressure switch and machine
ground.
Continuity
No Continuity
Bad (shorted) BR wire grounded in harnesses or
Go to Step 3.
connectors.
4-124
