OPERATOR'S STATION
TM 5-3805-263-14&P-3
PROBLEM A: One Or More Indicators Are ON.
Possible Causes:
If engine oil pressure indicator is ON (normal if engine oil pressure is
low: STOP ENGINE IMMEDIATELY).
a. Bad engine oil pressure switch.
b. An open (break) in a harness wire to the switch.
If engine coolant temperature and/or hydraulic oil temperature indicator is ON (If there
were a bad switch or harness, these indicators would have been ON in Test II;
therefore if any of them are ON now, it must be caused by a temperature problem),
follow the procedure given earlier for overheating.
If brake pressure indicator is ON and system pressure does not go above 75 psi (520
kPa) with engine running, there is a problem in the air system. (Any bad switches or
harness would have been taken care of in Test II.)
TROUBLESHOOTING
Engine Oil Pressure Indicator
Loss of engine oil pressure can cause much damage to the engine. If oil pressure
indicator turns ON, STOP VEHICLE AND THEN STOP ENGINE IMMEDIATELY.
Check engine oil level.
With the engine stopped and therefore no oil pressure, the oil pressure switch must
be open.
1. Remove the GY/R wire from the 9G8010 Engine Oil Pressure Switch and put it to
machine ground.
Indicator Turns ON
Indicator Does Not Turn ON
Operator panel and harness to the switch are good.
Go to Step 2.
Go to Step 3.
2. Connect the GY/R wire, that connects to the oil pressure switch, to machine ground.
Disconnect the harness plug from the operator panel and check for continuity
between connections 2 and 5. (Connection 2 is the system ground and connection 5
goes to the oil pressure switch.) Use a continuity tester or a digital multimeter.
4-37
