RED LIGHT 4C4579 - Caterpillar

Table 3
FMI 6 Troubleshooting
Troubleshooting Test Steps Values Results
1. Test The Operation Of The Hazardous Voltage Indicator Lamp
The key switch is in the OFF position. The Hazardous Voltage Indicator Lamp is not illuminated.
A. Access the disconnect switch and the Hazardous Voltage Indicator Lamp that are located under the access cover on the left-hand fender of the machine.
B. While observing the Hazardous Voltage Indicator Lamp, turn the disconnect switch to the OFF position and then turn the disconnect switch to the ON position. Hazardous Voltage Indicator Lamp illuminates briefly and then turns OFF. OK: When the disconnect switch is turned from the OFF position to the ON position, the amber Hazardous Voltage Indicator Lamp illuminates briefly and then turns OFF. This condition indicates that the operation of the lamp circuit IS correct. Proceed to Test Step 6.
NOT OK: When the disconnect switch is turned to the ON position, the amber Hazardous Voltage Indicator Lamp did not illuminate briefly and then turn OFF. Proceed to Test Step 2.
2. Check Power Circuit For A Short Circuit
A. Turn key switch and disconnect switch OFF.
B. At the Relay Fuse Panel, disconnect the yellow connector that connects the machine harness to the fuse panel connector. Verify that the connector is clean, dry and that all the contacts are in good condition. Verify that all the circuits are properly seated in the connector. Check the power supply circuit for the HV Present indicator wire A100-BK. Ensure that the socket is properly crimped on the wire and that the wire is not broken at the connector.
C. After checking the condition of the yellow connector and verifying that no problems have been found, connect the yellow connector to the mating connector on the fuse panel.
D. At the Relay Fuse Panel, remove the 10 amp Power Inverter-LED Fuse 9. An open fuse would not cause the ECM to activate the FMI 6 condition code, however, check the continuity between the fuse contacts when the fuse is removed.
E. At the hazardous voltage indicator, disconnect the machine harness connector for the LED indicator.
F. Turn the disconnect switch to the ON position. Turn the key switch to the ON position. DO NOT START THE ENGINE.
G. At the disconnected machine harness connector for the indicator, use a multimeter to check the DC voltage between contact 1 wire A100-BK and a good frame ground contact point. The voltage measurement indicates that little or no voltage is present in the power circuit. OK: The voltage measurement between the power circuit for the lamp and frame ground is indicating that little or no voltage is present on the power circuit. There does not appear to be a short circuit to another voltage source in the power circuit for the indicator. Proceed to Test Step 3.
NOT OK: Voltage is present between the power circuit for the lamp and frame ground. This indicates that there is a short circuit between the lamp power circuit in the machine harness, wire A100-BK, and another voltage source. Proceed to Test Step