Quick answer
Disconnect and switch off every load, keep a portable generator in its approved outdoor operating location, and record every indicator before resetting anything. Follow the model manual to check the output breaker, accessible GFCI devices, selector position, and one known-good compatible low-load appliance. If output does not return after one permitted reset, voltage is abnormal, protection trips again, or the problem exists inside the alternator, inverter, transfer switch, or panel, stop and arrange qualified service.
Define exactly where the power stops
Start with an observation map. Determine whether one receptacle is dead, every receptacle is dead, the generator receptacles work but the house does not receive power, or only some transferred circuits are unavailable. Record the generator display, output light, overload light, breaker position, GFCI state, transfer-switch indication, and whether the symptom began before or after a load was connected.
This distinction prevents a portable-generator outlet problem from being confused with a cord, inlet, transfer, load-management, or building-circuit problem. A running engine confirms only that the engine is operating. It does not confirm that the alternator or inverter is producing acceptable voltage and frequency, that the output breaker is closed, or that a connected transfer path is complete.
| Observed boundary | Owner-level observation | Next boundary |
|---|---|---|
| One receptacle only | Check its breaker or GFCI status and compare another approved outlet | Stop if the device will not reset or trips again |
| All generator outlets | Disconnect loads, review indicators, breaker and selector position | Service if one permitted reset does not restore output |
| Outlets work, house does not | Record cord, inlet and transfer indications without opening equipment | Qualified review of the connection and transfer path |
| Some transferred circuits only | Record which circuits work and any load-shed status | Review transfer, breakers, priorities and branch circuits |
Perform the permitted external checks with every load removed
Switch off and disconnect all loads before checking the generator output controls. Let the generator reach its normal operating state using the exact manual sequence. Check the generator main output breaker, individual receptacle breakers, accessible GFCI reset controls, economy mode, and any 120V or 120/240V selector only as the manufacturer directs. Do not change a selector under load unless the manual explicitly permits it.
If the manual permits a functional check, connect one known-good appliance whose voltage, plug, current and starting demand fit the selected receptacle. Use an intact cord rated for the load and environment. A successful small-load test does not approve the house connection or prove that the generator can support a larger motor start.
- Disconnect all loads before a reset
- Read indicators before clearing them
- Reset a breaker or GFCI only as the manual permits
- Use one known-good compatible low load
- Stop if protection opens again
Treat a generator that does not power the house as a separate path
When generator receptacles work but selected home circuits do not, the symptom is downstream of the generator outlet. Record the cord endpoint labels, inlet label, transfer or interlock position, generator breaker state, selected circuit breakers, load-management status, and any automatic transfer fault. Do not open an inlet, panel, or transfer enclosure to continue a remote checklist.
A 120V-only source, an incompatible neutral arrangement, an open transfer device, an incorrectly selected generator breaker, a failed cord, or a load-management decision can all produce different versions of “the generator is running but the house is dark.” Building equipment can contain utility voltage even while the generator is stopped, so diagnosis belongs with qualified personnel and the exact installation documents.
Leave excitation, brushes, AVR and inverter diagnosis to service procedures
Manufacturer troubleshooting may identify loss of residual magnetism, brushes, excitation components, an automatic voltage regulator, an inverter module, wiring, or an alternator as possible causes after external checks fail. Those possibilities are not interchangeable, and the safe test depends on the exact generator design.
Do not improvise field-flashing, backfeed a receptacle, apply an external source, remove an alternator cover, or probe live terminals from a generic article. Preserve the symptom, serial number, indicator state, load history and any fault code for an authorized service provider. That evidence is more valuable than a reset that temporarily hides the condition.
Return the generator to service only after a controlled load test
After a permitted correction or qualified repair, start with no connected loads and confirm normal indicators. Add verified loads in a documented sequence while remaining within the generator, receptacle, cord and transfer ratings. Note voltage or frequency readings only when the equipment and operator are qualified for that measurement.
Record the original symptom, weather, fuel, runtime, connected loads, protection state, corrective action and test result. If the failure returns, keep the generator unavailable until it is diagnosed. Critical loads need a separate contingency instead of repeated resets during an outage.
Frequently asked questions
Common questions
Why does my generator run but not produce electricity?
External causes can include an open output breaker, tripped GFCI, incorrect selector position, faulty load or cord, and a downstream transfer-path problem. If one permitted external reset does not restore output, internal diagnosis requires model-specific service.
Can I test the generator with a small appliance?
Only if the manual permits it and the appliance, plug, voltage, current, starting demand and cord all fit the receptacle. Disconnect all other loads first.
Why do the generator outlets work but the house has no power?
The problem may be in the cord, inlet, generator breaker, transfer equipment, load-management system or building circuits. Record the visible states and obtain qualified review without opening energized equipment.
Should I field-flash a generator that has no output?
Do not follow a generic field-flashing method. Generator designs differ, and applying an external electrical source can be hazardous. Use the exact manufacturer service process or an authorized technician.
Primary references
CordFind summarizes connector specifications and public safety guidance. Always follow the instructions supplied with your equipment.