Generator running but no power? How to find the fault

Try these first

1. Unplug everything from the generator.
2. Plug in one simple appliance you know works, like a box fan. Generac suggests exactly this test.
3. Check every circuit breaker on the generator's panel. Reset any that have tripped.
4. Look at the lights. Is an overload light on? Is the green output light on?
5. On an inverter model, stop the engine and restart it.
6. Try a different outlet on the generator, and a different cord.

A tripped breaker or overload

Symptom: The engine runs, but the outlets are dead. An overload light may be on.

Why it happens: Breakers trip to protect the generator. Honda's inverter cuts power to the outlets about four seconds after an overload or short, but keeps the engine running. So the engine sounds fine while the outlets are dead.

How to check and fix it:

1. Unplug everything.
2. Reset the breaker or circuit protector. Honda says to check the AC load and reset it.
3. On an inverter model where the overload light is on, Honda says to stop and restart the engine. It also says to check the cooling air inlet isn't blocked, since the inverter can shut off if it overheats.
4. Plug loads back in one at a time. If one trips it again, see overload light and tripping.

The cord or the appliance is the problem

Symptom: The box fan works when plugged straight in, but your cord or appliance doesn't.

Why it happens: Champion's "no AC output" list starts with a cable not properly connected and a defective device. Honda lists "faulty power tool or appliance."

How to check and fix it:

1. Plug the working fan straight into the generator.
2. Then plug it in through your extension cord.
3. If the fan works direct but not through the cord, replace the cord.
4. If the fan works but your appliance doesn't, the appliance is the fault.

Power doesn't reach the house

Symptom: The generator's own outlets work, but nothing in the house comes on.

Why it happens: Home connections go through a transfer switch or an interlock, installed by an electrician. If that switch isn't set to generator, or its breaker is off, power won't reach your circuits.

How to check and fix it: Follow the switching steps your electrician gave you. See interlock vs transfer switch for how each one works.

Never plug a generator into a wall outlet to power the house. CPSC calls this "backfeeding" and says it is extremely dangerous. It puts utility workers and neighbors at risk of electrocution.

A conventional generator lost its magnetism

Symptom: A conventional (non-inverter) generator runs, the breakers are fine, and the box fan still gets nothing. It often shows up after the generator has been in storage.

Why it happens: Generac explains that generators in storage "can lose their magnetism and fail to produce electricity, even when the engine is running." The alternator needs a little leftover magnetism in the rotor to start making power.

How to fix it: flash the field (Generac's drill method)

This is Generac's method for its portable generators. Check your own manual first. Some makers use a different method, and it does not apply to inverter generators. If you're not comfortable with it, have it serviced instead.

Electrical caution: you'll be working next to a running generator with live outlets. Keep your hands dry, stand on dry ground, use a drill with an undamaged cord, and touch nothing but the drill.

1. Start the generator and let it run. Place it outdoors, as always.
2. Plug a corded electric drill into one of the generator's outlets. Generac notes a cordless drill will not work.
3. If the drill is reversible, set it to forward.
4. Hold the trigger in, and spin the drill chuck by hand in the reverse direction 3 to 5 times.
5. The drill should start running on its own. That means the generator is making power again. Generac warns the drill will start working as soon as the field is excited, so hold it firmly.
6. If nothing happens, spin the chuck the other way. The reverse switch may be set backwards.

If flashing doesn't work, Generac says you may have other problems. It suggests the brushes may need replacing on a brushed alternator, and says to take it to a service dealer.

A failed voltage regulator, brushes or inverter

Symptom: Nothing above fixed it.

Why it happens: Champion's list ends with a faulty brush assembly and a faulty AVR (automatic voltage regulator), both as Service Center jobs. Honda says a blinking overload light on its inverter models points to an inverter fault, which needs a dealer.

How to fix it: Have it serviced. These parts sit inside the alternator and control panel, where there's high voltage.

When to stop and call a pro

Call a service dealer if:

• Flashing the field didn't help, or you'd rather not do it.
• An inverter model's overload light blinks continuously.
• You smell burning from the alternator or panel.
• The generator is under warranty. Opening the panel can void it.

Run it outdoors only, 20+ feet from the house: generator carbon monoxide safety.