System 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 Module
Test 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.
STOP
Test 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.
STOP
Test 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 - There is no short circuit condition present in the harness. Proceed to Test Step 7.
- NOT OK - There is a short circuit condition present in the harness.
Repair: Repair or replace the harness.
STOP
Test Step 7. CHECK FOR AN OPEN POWER CIRCUIT IN THE HARNESS.
- Check the Display harness for a open circuit condition.
Note: Use the machine schematic to identify the power circuit wiring.
Expected Result:
There is no open circuit condition present in the harness.
Results:
- OK - There is no open circuit condition present in the harness. The power module (if equipped) has failed.
Repair: Replace the power module.
STOP
- NOT OK - There is an open circuit condition present in the harness.
Repair: Repair or replace the harness.
STOP