PLATE 3129376 - Caterpillar

Operation Description:There is no power to the GPS Receivers.The following are possible causes:
Display not turned on
Fuse blown or Open Circuit Breaker
Damaged harness or connector
Failed receiver
Power Jumper
Power ModuleTest Step 1. VERIFY THE DISPLAY WILL TURN ON.
Ensure the battery disconnect switch and the key start switch are in the ON position.
Turn the display ON.Expected Result:The display turns ON.Results:
OK - The display turns ON. Proceed to Test Step 2.
NOT OK - The display does not turn ON.Repair: Perform the "Display Does Not Turn ON" procedure.STOPTest Step 2. VERIFY THE GPS RECEIVERS POWER UP.
Verify that the power LED on the GPS receiver(s) is illuminated.Expected Result:All three of the light bars are illuminated.Results:
OK - The power LED on the GPS receiver(s) is illuminated.STOP
NOT OK - The power LED on the GPS receiver(s) is not illuminated. Proceed to Test Step 3.Test Step 3. CHECK THE POWER TO THE GPS RECEIVERS.
Disconnect the harness connectors from the GPS receiver connectors.
Measure the voltage between pin A and pin F on the harness connector for the receiver.Expected Result:The measured voltage is approximately machine voltage at each machine harness connector for each GPS receiver.Results:
OK - The measured voltage is approximately machine voltage at each machine harness connector for each GPS receiver. The GPS receiver has failed.Repair: Replace the failed GPS receiver.STOP
NOT OK - The voltage is not approximately machine voltage at each machine harness connector for each GPS receiver. Proceed to Test Step 4.Test Step 4. CHECK FUSE OR CIRCUIT BREAKER.
Check the fuse or circuit breaker.Note: Use the machine schematic in order to identify the correct fuse or circuit breaker.Expected Result:The fuse or the circuit breaker is OK.Results:
OK - The fuse or the circuit breaker is OK. Proceed to Test Step 5.
NOT OK - The fuse or the circuit breaker has failed.Repair: Replace the fuse or the circuit breaker.STOPTest Step 5. CHECK FOR AN OPEN POWER JUMPER IN THE POWER CIRCUIT IN THE HARNESS.
Use the AccuGrade electrical schematic for the machine in order to determine if a power jumper is used.
Place a jumper between pin B and pin C at the connector of the Display harness.
Turn the display ON.Expected Result:The GPS Receiver(s) power up.Results:
OK - The power jumper has failed.Repair: Replace the power jumper.STOP
NOT OK - The GPS receiver(s) do not power up. The power jumper is not the cause of the failure. Proceed to Test Step 6.Test Step 6. CHECK FOR A SHORTED POWER CIRCUIT IN THE HARNESS.
Check the Display harness for a short circuit condition.Note: Use the machine schematic to identify the power circuit wiring.Expected Result:There is no short circuit condition present in the harness.Results:
OK