Onan 26 fault code — Generator
Applies to: QG 7000i DF HGLCA Spec A
What 26 means
The Cummins Onan QG 7000i DF HGLCA operator manual list Code 26 as Alternator Undervoltage.
Owner-safe checks
- Reduce connected loads, especially air conditioners and battery chargers.
- Record whether the fault clears with fewer loads.
Service-only work
- Internal generator electrical output, inverter, controller, sensors, fuel system, ignition, AC circuit, and engine diagnosis belongs to Cummins service or a qualified generator technician.
Safety boundary
Generators can produce carbon monoxide, hot surfaces, fuel hazards, moving-part hazards, and lethal voltage. Shut the generator down and do not open energized compartments unless qualified.