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
4. Turn the fuel OFF.
Remove the oil pressure switch and put a thumb over the opening.
Have another serviceman turn the Power Key Switch to the START position so
that the starter motor turns the engine. (Do not turn the engine for more than 30
seconds).
An increase in oil pressure must be felt.
Oil Pressure Is Felt
Oil Pressure IS Not Felt
Install a pressure gauge in the opening for the pres-
Make repairs as necessary.
sure switch and make a test for oil pressure. If oil
pressure is correct, make a replacement of the oil
pressure switch. If oil pressure is not correct, make
repairs as necessary.
Brake Air Pressure Indicator
The brake foot lever controls the air supply to each brake master cylinder. If the
air pressure for this system is low, the 9G8009 Brake Air Pressure Switch opens
and turns on the indicator.
1.
2.
3.
1.
Let engine run for several minutes to be sure there is enough air pressure.
Check for air leaks, especially at drain valves on air reservoir.
Check brake fluid level.
ELECTRICAL TROUBLESHOOTING
Remove the Y/W wire from the 9G8009 Brake Air Pressure Switch and put
it to machine ground. If the indicator turns OFF, the problem is in the switch or
its harness.
Indicator Turns OFF
Indicator Does NOT Turn OFF
Go to Step 2.
Problem is in the operator panel or the harness from
the panel to the switch.
2. Check for continuity across the 9G8009 Brake Air Pressure switch (wires).
Use an 8S4627 Circuit Tester.
Continuity
No Continuity
Open wire from switch to ground. Repair or replace.
Replace the switch.
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