Why your generator runs but doesn’t have power

You fire up your generator, and the engine’s humming along nicely, but there’s a problem—nothing’s getting powered! It doesn’t make sense when the engine seems fine, right? If your generator runs but isn’t producing any electricity, let’s figure out why and see what you can do to fix it.

This information might not match your specific appliance model. We aim to offer useful advice for all sorts of DIY appliance repairs, but different models and setups can mean the steps to troubleshoot, error codes, part replacements, etc., may vary. For the most accurate help, we recommend checking out your appliance’s manufacturer documentation or contacting us if you’ve got any questions.

Common reasons your generator isn’t producing power

• The generator is losing residual magnetism: Generators rely on leftover magnetism in the rotor’s iron core to start generating electricity. This magnetism can fade over time, especially if the generator hasn’t been used for a while or was stored improperly.
• Breaker trips: A tripped breaker cuts off the electrical flow to prevent damage. If the breaker’s tripped, it cuts off power output even though the engine’s running.
• Brushes malfunction: Generators that use brushes rely on these parts to transfer electrical current between stationary wires and the rotating shaft. If the brushes are worn out or defective, they can mess up this transfer, leading to no power output.
• Capacitor is faulty (in brushless generators): Brushless generators use capacitors to induce voltage. If the capacitor’s faulty, it can’t properly store or release electrical energy, stopping the generator from producing power.
• AVR malfunctions: The AVR keeps voltage levels steady. If it’s not working right, voltage regulation fails, and the generator might not output any power.
• Outlet is faulty: A damaged or faulty outlet on the generator can stop power from reaching your devices. Common causes are physical wear or internal wiring issues.

How to troubleshoot and fix the issue

Check for tripped breakers

Resetting the breaker is a simple fix that often works if a power surge or overload causes it to trip.

1. Find the breaker switch on your generator.
2. Make sure the switch is in the “On” position. If it’s flipped to “Off,” reset it by flipping it back to “On.”
3. Test the generator by plugging in a small load, like a light bulb, to see if power’s back.

Inspect and replace brushes

1. Turn off the generator and disconnect the spark plug for safety.
2. Access the brushes by removing the generator’s end cover.
3. Check the brushes for wear or damage. They should be at least half an inch long.
4. If they’re worn, replace them with new brushes compatible with your generator model. Check the manufacturer’s documentation or find your appliance’s model number for the right parts.
5. Put everything back together and test for power output.

Test and replace the capacitor

A working capacitor is essential for voltage induction in brushless generators.

1. Make sure the generator is off and unplugged.
2. Locate the capacitor, usually near the alternator.
3. Safely discharge the capacitor by placing a resistor across its terminals.
4. Carefully remove the capacitor.
5. Use a multimeter set to resistance (ohms) mode to test it.
6. The multimeter should show low resistance at first, then gradually move toward infinity (open circuit) as the capacitor charges from the meter’s battery.
7. Connect the multimeter leads to the capacitor terminals.
8. If the resistance stays low (meaning a short) or shows infinite resistance right away (meaning an open circuit), the capacitor is probably bad.
9. If it’s faulty, replace it with a new capacitor that matches the specs.
10. Reassemble and test the generator.

Address AVR problems

The AVR makes sure your generator provides consistent voltage, so if it’s not working, it can stop power production.

1. Turn off the generator and disconnect all power sources.
2. Find the AVR, typically mounted near the alternator.
3. Look over the AVR for signs of damage, like burnt components or loose connections.
4. Test the AVR using a multimeter set to resistance (ohms) mode.
5. Disconnect the AVR from the generator.
6. Refer to the manufacturer’s documentation for the correct resistance values between the AVR terminals.
7. Measure the resistance across the input and output terminals.
8. Compare the readings with the specified values. Big differences mean the AVR might be faulty.
9. If the AVR is bad, replace it with one that’s compatible with your generator model.
10. Reconnect everything and test for power output.

Fix generator’s loss of residual magnetism (flash the generator)

Safety Note: Be careful when handling batteries and electrical components. Wrong connections can cause damage or injury.

Flashing the generator brings back the residual magnetism needed to generate power.

1. Get a 6-volt to 12-volt DC battery (like a car battery).
2. Find the field winding terminals on the generator. Check your generator’s manual or contact us if you’re not sure.
3. With the generator off, connect the positive (+) terminal of the battery to the positive field winding terminal.
4. Connect the negative (-) terminal of the battery to the negative field winding terminal.
5. Hold the connection for about 3-5 seconds. This re-magnetizes the rotor.
6. Disconnect the battery and start the generator.
7. Test the generator by connecting a load to see if power’s restored.

Test and replace a bad outlet

A good outlet is necessary to deliver power from the generator to your devices.

1. Turn off the generator and disconnect all power sources.
2. Look at the outlet for any visible damage, like cracks or burn marks.
3. Use a multimeter set to resistance (ohms) mode to test the outlet:
4. Access the wiring terminals of the outlet.
5. Check the continuity between the terminals. There shouldn’t be continuity between the hot and neutral or ground terminals.
6. If there’s continuity, the outlet might be shorted and needs to be replaced.
7. If the outlet’s faulty, replace it with one that matches your generator’s specs.
8. Put everything back together and test for power output.

Get your generator back up and running

Dealing with a generator that runs but doesn’t produce power can be a real hassle, but with these troubleshooting steps, you can often figure out and fix the problem yourself. 

For replacement parts and more repair help, visit us at AppliancePartsPros.com. We’re here to support your DIY repair journey every step of the way.

Stay connected with us for more tips and updates by following us on Facebook and Twitter. If you’ve got any questions or need personalized assistance, don’t hesitate to contact us. We’re always ready to help you keep your appliances running smoothly.