Generator not putting out power: causes, part cost
Prices checked 2026-08-28
A generator not putting out power is most often a tripped internal breaker problem - about 30% of reported jobs. Here is how to confirm it, what the part costs, and when to stop.
A generator is an engine turning an alternator, and it fails on whichever side you neglected – fuel and carburettor on the engine side, brushes and AVR on the alternator side.
Generator not putting out power is one of the most common repair searches there is. A generator that runs but produces no power has failed in the generation or regulation side – brushes, the AVR, or the breaker between the generator and your loads.
Before you call anyone: 30-second checks
- Check the generator's own breaker and outlet – the most common "no power" is a tripped breaker.
- Check the brushes and slip rings on the alternator – a common wear item.
- Check the AVR (voltage regulator) if output is low or unstable.
The likely causes, ranked
Tripped internal breaker
About 30% of generator not putting out power jobs come back to this cause. A tripped breaker, GFCI or reset button is the electrical system protecting the circuit – and the cheapest "fault" on the list.
How to confirm it: Check the panel and any GFCI outlets on the circuit; if the breaker trips again immediately, the fault is in the unit or the wiring, not the breaker.
Typical fix: usually free. A capable DIYer can usually handle this one.
Failed capacitor or AVR
About 26% of generator not putting out power jobs come back to this cause. A motor, fan or pump with its drive components is a wear item – belts stretch, bearings dry out, capacitors lose their charge and relays stick.
How to confirm it: Listen for the motor: a hum with no movement points at a capacitor or belt; a grinding or squeal points at a bearing. Each has a different price tag.
Typical fix: $90. A capable DIYer can usually handle this one. You would be looking for a AVR capacitor.
Worn brushes
About 24% of generator not putting out power jobs come back to this cause. This is a component-level failure – the part itself has worn out or failed, which is why it sits on the ranked list rather than the free-check list.
How to confirm it: It is worth confirming with a multimeter or a visual check before ordering the part, and worth asking the shop if the part is returnable.
Typical fix: $60. A capable DIYer can usually handle this one. You would be looking for a brush set.
Alternator winding fault
About 20% of generator not putting out power jobs come back to this cause. This is a component-level failure – the part itself has worn out or failed, which is why it sits on the ranked list rather than the free-check list.
How to confirm it: It is worth confirming with a multimeter or a visual check before ordering the part, and worth asking the shop if the part is returnable.
Typical fix: $200. This one is best left to a professional.
When to stop and call a pro
Alternator work is electrical work – the parts are cheap but the diagnosis needs a meter. If the checks above do not find it, a small-engine shop is usually worth the visit.
How to keep it from coming back
Generators need to run under load occasionally to keep the alternator healthy; a unit stored for a year without a run develops exactly these faults.
Bottom line: Generator not putting out power is worth diagnosing before you call anyone – the free checks above catch a surprising share of cases, and the ranked list tells you what the part should cost if it is not one of them. Run the figures through the repair-or-replace test on this page before you authorise any work, and never pay for a diagnosis without getting the part name and the price in writing first.
Likely causes, most common first
| Likely cause | How often | Typical fix | Who does it |
|---|---|---|---|
| Tripped internal breaker | 30% | free | DIY-able |
| Failed capacitor or AVRAVR capacitor | 26% | $90 | DIY-able |
| Worn brushesbrush set | 24% | $60 | DIY-able |
| Alternator winding fault | 20% | $200 | Pro job |
Frequencies are the share of reported jobs attributed to each cause across repair-platform and forum data - a starting point for diagnosis, not a certainty.
What this should cost to put right
Across the causes listed above the repair runs $0 to $200. A quote far above the top of that range is usually a diagnosis of convenience - get a second opinion before you authorise it.
Repair it, or replace the unit?
This is the number people get wrong most often, and it costs them the most. Run the quote through the test - it uses the mid-point cost of the fix above against a new unit and the years this one has left.
REPAIR IT
The repair is 11% of a new unit and the appliance has roughly 5 year(s) of expected life left. Fixing it is the economical call. A new unit would save about $45/year in running costs, so keep repairing until that pays back in under 5 years.
Decision rule: repair when the fix costs under 50% of a replacement and the unit is under 70% through its expected life.
Other generator symptoms
Common questions
Is it dangerous if my generator has a "not putting out power" problem?
Usually not immediately - none of the likely causes on this page involve gas, fuel or a mains electrical fault. The two cautions that apply everywhere: keep water away from any electrical point, and if you ever smell gas or burning, stop diagnosing and call a professional.
How much does it cost to fix a generator with a "not putting out power" problem?
Most fixes for this run $0 to $200. The most common cause, tripped internal breaker, runs about nothing - it is a free check to put right, and the part you would be looking for is not usually sold separately. Get the diagnosis in writing before authorising anything above the top of the range.
Why does my generator have a "not putting out power" problem?
In about 30% of reported cases it is a tripped internal breaker. It is the first thing to check because it is the most common - and usually the cheapest. If that checks out clean, work down the ranked list on this page before paying for a diagnosis.
Should I repair or replace my generator?
Repair it when the fix costs under half of a replacement and the unit is under 35% through its roughly 12-year expected life. Past that point a repair is usually a deposit on the next failure - run the test on this page with your actual quote before you decide.
How this figure was built
Reviewed 2026-08-28 · quarterly.
- Bureau of Labor Statistics, Occupational Employment and Wage Statistics - construction and repair trades
- EPA Energy Guide appliance ratings
- North American Electrical Metrics / manufacturer parts catalogues
National averages. Local labour can run 20-40% above or below these figures; the calculators apply a metro factor on top.
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