Cummins/Onan K1000 troubleshooting: 4 fault codes and 41 symptom-cause-remedy entries from the manufacturer's own service documentation.
Cummins/Onan K1000 — full specs, parts & maintenance.
All Cummins/Onan fault codes →
| Code | Meaning | Remedy |
|---|---|---|
| OV | Output voltage | Set the switch to the desired AC or DC position |
| 3 ~ 6V | Only slight output voltage is delivered (3 ~ 6V) | Repair or replace. |
| OV | Output voltage | Set the switch to the desired AC or DC position |
| 3 ~ 6V | Only slight output voltage is delivered (3 ~ 6V) | Repair or replace. |
| Symptom | Cause | Remedy |
|---|---|---|
| Voltage indication lamp lights, but output voltage is not delivered | Switch is not at (DC, AC) position | Set the switch to the desired position. |
| Voltage indication lamp lights, but output voltage is not delivered | Disconnected main coil | Repair or replace. |
| Voltage indication lamp lights, but output voltage is not delivered | Blown fuse | Locate the cause (short circuit caused by overloaded wiring, etc.) and remove it. Then, replace fuse. |
| Voltage indication lamp lights, but output voltage is not delivered | Improper contact of receptacle | Repair or replace. |
| Voltage indication lamp lights, but output voltage is not delivered | Improper switch contact | Repair or replace. |
| Voltage indication lamp lights, but output voltage is not delivered | Disconnected wiring (rear side of control panel) | Check wiring. Repair. |
| Voltage indication lamp does not light and output voltage is not delivered | Disconnected main coil | Repair or replace. |
| Voltage indication lamp does not light and output voltage is not delivered | Disconnected rotor coil | Repair or replace. |
| Voltage indication lamp does not light and output voltage is not delivered | Disconnected rotor diode | Replace. |
| Voltage indication lamp does not light and output voltage is not delivered | Defective capacitor | Replace. |
| Voltage indication lamp does not light and output voltage is not delivered | Disconnected sub coil | Repair or replace. |
| Rated output is not available | Shorted stator coil (including sub coil) | Repair or replace. |
| Rated output is not available | Disconnected or shorted rotor coil | Repair or replace. |
| Rated output is not available | One of rotor diodes defective | Replace. |
| Rated output is not available | Defective diode stack | Replace. |
| Large difference between voltages with load and without load | Disconnected main capacitor coil | Repair or replace. |
| Large difference between voltages with load and without load | Defective main capacitor | Replace. |
| Voltage indication lamp does not light | Defective voltage indicator | Replace. |
| Fuse blows frequently | Overload, short circuit of wiring | Remove overload or repair. |
| Fuse blows frequently | Abnormal load | Repair load. |
| Pilot lamp lights but output voltage is not delivered | Faulty contact of receptacles | Repair or replace. Checking wiring. |
| Pilot lamp lights but output voltage is not delivered | Disconnected wiring (inside of control box) | Repair. |
| Pilot lamp does not light and output voltage is not delivered | Circuit breaker "OFF" | Locate the cause (overload, short circuit of wiring). Replace circuit breaker after removing the cause. |
| Pilot lamp does not light and output voltage is not delivered | Disconnected output coil | Repair or replace stator. |
| Pilot lamp does not light and output voltage is not delivered | Demagnetization of permanent magnet | Replace. |
| Pilot lamp does not light and output voltage is not delivered | Disconnected wiring | Repair. |
| Pilot lamp does not light and output voltage is not delivered | Disconnected rotor coil | Repair or replace. |
| Pilot lamp does not light and output voltage is not delivered | Worn brush or faulty contact surface and slip ring | Clean brush contact surface and slip ring or replace brush. |
| Pilot lamp does not light and output voltage is not delivered | Disconnected sub coil | Repair or replace. |
| Pilot lamp does not light and output voltage is not delivered | AVR failure | Replace. |
| Circuit breaker blows | Abnormal load circuit | Remove abnormality in load circuit (overload, short circuit) and replace fuse. |
| Rated output is not available | Disconnected or punctured AVR capacitor (220uF) | Replace capacitor. |
| Rated output is not available | Faulty contact of AVR connector | Repair. |
| Rated output is not available | Faulty brush contact | Check for wear, wear amount, and contamination of contacting surface of brush and clean if necessary. |
| Rated output is not available | Excessive initial current | Locate the cause (overload) and remove it. |
| Rated output is not available | Low engine output | Repair engine. |
| Rated output is not available | Faulty engine governor | Repair engine. |
| Rated voltage is not available | Low engine revolution (below 2500 rpm) | Set the accelerator lever to the operating position. |
| Rated voltage is not available | Shorted stator coil (including sub coil) | Repair or replace. |
| Rated voltage is not available | Shorted rotor coil | Repair or replace. |
| Rated voltage is not available | Defective AVR | Replace. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Shorted stator coil (including sub coil); Disconnected or shorted rotor coil; One of rotor diodes defective; Defective diode stack. See the table for the matching fixes.
Documented causes: Circuit breaker "OFF"; Disconnected output coil; Demagnetization of permanent magnet; Disconnected wiring. See the table for the matching fixes.
Documented causes: Switch is not at (DC, AC) position; Disconnected main coil; Blown fuse; Improper contact of receptacle. See the table for the matching fixes.