Service Manual

7. Troubleshooting 10-2019
168 A062J683 (Issue 1)Copyright © 2019 Cummins Inc.
Diagnosis & Repair:
1. Check the last fault recorded.
• If this fault has not been repaired, troubleshoot that fault.
2. Inspect slip rings and clean them as required.
3. Disconnect the generator set control P1 connector.
4. Measure the quadrature winding resistance between pin sockets P1-2 and P1-
3; compare that to the value in the table in the Alternator section.
a. If open or shorted, measure quadrature winding resistance at pins of AC-J
1 and 2 and compare to table value.
• If not within range, replace the alternator.
b. If acceptable, check for continuity between P1-2 and AC-P 1, and also P1-
3 and AC-P 2.
• If open or shorted, repair or replace the harness.
5. Verify that the P1 pin socket is fully inserted and inspect the pin socket
condition for corrosion and acceptable condition of contact wipers. To check
contact wipers, use one of the devices below:
• A mating pin connector
• A pin gauge the same size as the mating control connector pin (0.045 in)
• Any suitable device that will not damage the inside contact wipers of the
pin socket
If necessary:
• Clean, repair or replace the pin socket.
• Fully insert any partially inserted pin socket.
6. Inspect the condition of the P1 pin on the control board. If it is damaged or
severely corroded, clean or repair if possible, or replace the control board.
7. When reconnecting the harness plug to the connector, ensure that the pair are
fully seated next to each other.
8. Reconnect the P1 connector and test-run the generator set for fault occurrence.
9. Measure the AC current while running the generator set with loads.
• Identify faulty or short cycling loads.
Code 46 - Generator Set Overload
Logic: The total generator set load is above 105% of rated.
Possible Causes: Excessive load connected to the generator set
Diagnosis & Repair:
1. Check the last fault recorded.
• If this fault has not been repaired, troubleshoot that fault.