HEAD AS 2502253 - Caterpillar

Fault Identification
Check the excitation.
Use a multimeter across the exciter field outputs F1 and F2. A multimeter should be set for VDC. Another way to verify that the regulator is providing excitation is by looking at parameter :55. Parameter :55 describes excitation current.Expected Result: The regulator is providing excitation to the generator.Results:
OK: Go to Step 2.
NOT OK: Go to Step 4.
Check the status of the alarm.
Check the display on the digital voltage regulator.
Check the status of the alarm output.Expected Result: The display on the digital voltage regulator is flashing or the alarm output is off. When alarm output is off, an alarm is active.Results:
OK: An alarm has occurred. The alarm is active. No new alarms will be detected until the fault has been reset. However, fault detection is still enabled. Go to Step 5.
NOT OK: Go to Step 3.
Check the status of the latest fault.
Check if a new alarm has been logged in parameter :92. Parameter :92 describes the latest fault.Expected Result: A new alarm has been logged in parameter :92.Results:
OK: A fault or alarm has occurred and has been reset. Troubleshoot the problem using the code in parameter :92 and the service manual (or clear the alarm). Go to Testing And Adjusting, "Fault Handling", section Fault Clearing.
NOT OK: No new alarm has occurred. STOP.
Check the status of the fault.
Check the display on the digital voltage regulator.
Check the status of the fault output.Expected Result: The display on the regulator is flashing or the fault output is off. When fault output is off, a fault is active.Results:
OK: A shutdown fault has occurred and is active. No new alarms/faults will be detected until this fault is reset. Go to Step 5.
NOT OK: Refer to Testing And Adjusting, "Troubleshooting". STOP.
Check the shutdown fault log.
Check the number logged in the shutdown fault log. The shutdown fault log is described by parameter :92. Check the flashing number on the display.Expected Result: The number starts with a 6 (6xx).Results:
OK: The number starts with a 6 (6xx). An alarm has occurred. This will not shut down the digital voltage regulator. The alarm is resettable without removing power by activating either parameter :96, the external fault reset switch contact, or by cycling the 24 VDC. Follow the troubleshooting procedures in the service manual for the alarm code shown in parameter :92. Continue the procedures until the alarm has been reset.
NOT OK: The number does not start with a 6 (6xx). Go to Step 6.
Check the shutdown fault log (continued).
Check the number logged in the shutdown fault log. The shutdown fault log is described by parameter :92. Check the flashing number on the display.Expected Result: The number starts with a 7 (7xx).Results:
OK: The number starts with a 7 (7xx). A resettable fault has occurred. This fault is resettable without removing power by activating either the shutdown fault reset parameter :96, the external fault reset switch, or by cycling the 24 VDC. Follow the troubleshooting procedures in the service manual for the fault code shown in parameter :92 and