System Operation Description:
The light bars are not receiving power.
The probable conditions that cause this symptom are in the following list:
- The light bar brightness is set to 0
- The display is not turned on
- Damaged harness or connector
- Failed light bar
Test Step 1. VERIFY THE BRIGHTNESS SETTING OF THE LIGHT BAR.
- Select "Display and Light Bar Brightness" in the "Configuration" menu.
- Ensure that the "Display and Light Bar Brightness" is not set to 0. If the setting is 0, set it to a higher number until the light bars illuminate.
- Verify that the display will power up.
- 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 LIGHT BARS POWER UP.
- Check if the light bars are illuminated.
Expected Result:
All three of the light bars are illuminated.
Results:
- OK - The light bars are illuminated.
Repair: The problem was caused by the Display being turned off. Return the machine to service.
STOP
- NOT OK - One or more of the light bars do not power ON. Proceed to Test Step 3.
Test Step 3. CHECK THE POWER TO THE LIGHT BARS.
- Disconnect the harness connector from light bar connectors.
- Measure the voltage between pin 1 and pin 2 of all three connectors for the light bar.
Expected Result:
The measured voltage is approximately machine voltage at each machine harness connector for each light bar.
Results:
- OK - The measured voltage is approximately machine voltage at each machine harness connector for each light bar. The light bar(s) that did not illuminate have failed.
Repair: Replace the failed light bar(s).
STOP
- NOT OK - The voltage is not approximately machine voltage at each machine harness connector for each light bar. 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 circuit breaker is "OK".
Results:
- OK - The fuse or the circuit breaker is OK. Proceed to Test Step 5.
- NOT OK - The fuse or circuit breaker have failed.
Repair: Replace the fuse or circuit breaker.
STOP
Test Step 5. CHECK FOR A SHORTED POWER CIRCUIT IN THE HARNESS.
- Check the 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 6.
- NOT OK - There is a short circuit condition present in the harness.
Repair: Repair or replace the harness.
STOP
Test Step 6. CHECK FOR AN OPEN POWER CIRCUIT IN THE HARNESS.
- Check the 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. Proceed to Test Step 7.
- NOT OK - Repair the harness or replace the harness.STOP
Test Step 7. CHECK THE LIGHT BARS.
- Reconnect the three light bars.
- Turn the disconnect switch and the key start switch to the ON position.
- Verify that the three light bars are illuminated.
Expected Result:
The three light bars are illuminated.
Results:
- OK - The three light bars are illuminated.
Repair: A poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected probably caused the initial problem with the light bars. Resume normal machine operation.
STOP
- NOT OK - One or more of the light bars are not illuminated.
Repair: Repeat this procedure.
STOP