Why Does My Onan Generator Keep Shutting Off?

Why Does My Onan Generator Keep Shutting Off?

There might be several reasons why does my Onan generator keep shutting off? The generator frequently shuts down without warning, which is one problem. While there are several potential explanations for this, we’ll focus on some of the most prevalent ones in this article. Understanding these problems will help you troubleshoot What To Do Why does Onan generator keeps shutting off so that your generator will function properly when you need it.

What Is An Onan Generator?

An Onan generator is a particular type of generator that runs on gasoline and is one of the most common generators used in recreational vehicles, boats, and campers.

What Causes The Generator To Shut Off?

Your Onan generator might turn off abruptly for various causes, such as:

  • Low crankcase oil levels
  • A filthy air filter
  • The need for replacement spark plugs
  • A loose or damaged ground wire connection on the generator or control box
  • A loose or damaged ground wire connection on the generator head

Why Does My Onan Generator Keep Shutting Off? 5 Possible Reasons

Onan generator is one of the most popular generator types seen in campers, watercraft, and RVs. Several potential reasons your Onan generator can be abruptly switched off. These include difficulties with the ground wire connection on the generator or the control box, as well as problems with the generator head being loose or damaged.

The Crankcase Has Insufficient Oil

The “low oil pressure” shutdown switch or the oil level switch is often to blame when low oil levels in the generator’s crankcase force the engine to shut down. Together, these two switches measure the amount of oil in the crankcase, and if they detect that the oil level is too low, they will cause the engine to shut down.

Spark Plugs Should Be Replaced.

If the spark plugs need to be changed, the generator may suddenly stop working for a few reasons, such as: – Using more gas. It puts more stress on the engine and could cause it to break down sooner.

The Generator Head Slips Loose Or Is Somehow Harmed

The engine may abruptly shut down if the generator head loses or sustains some damage. The generator head is a crucial component of the machine. Therefore if it is broken or gets loose in any way, it usually triggers further, equally serious problems. It can include

  • Worn-out gaskets for the cover plate or elsewhere on the generator
  • Broken generator head nuts
  • Loose generator head bolts
  • A damaged gasket on the generator’s cover plate or elsewhere.

A Loose Or Corroded Connection On The Generator’s Ground Wire

Your Onan generator may have a ground wire connection that is either loose or corroded. This can lead to a number of problems, including a decrease in the engine’s performance, a reduction in the efficiency with which it burns fuel, an increase in the stress placed on the engine, and an increase in the likelihood that the engine will fail prematurely.

A Control Box Ground Wire Connection That Is Loose Or Corroded

Additionally, a weak or rusty ground wire connection on the control box will cause the generator to turn off abruptly, lowering engine performance and reducing fuel efficiency. It will also stress the engine and hasten its early demise.

Additionally, examine the fuel system for air leaks. You are more likely to detect leaks if you are on board with your generator. Skimmers are substantially more challenging to find because of the system’s high pressure.

Take steps to address the problem and resume enjoying your generator if you discover one of these items is causing your generator to shut off. Utilize this generator service manual to learn everything there is to know about this issue and how to resolve it.

What Are Some Common Problems With Onan Generators?

Your generator might be abruptly turning off for several different causes. Some possibilities include:

  • Shut-off switches
  • Low oil level
  • Failing voltage regulator
  • Incorrect carburetor settings
  • Weak batteries
  • Faulty spark plug
  • Dirty air filters or mufflers
  • Loose connections
  • Wrong type of fuel is being used

These are a few problems that could be causing the shutdown you’re experiencing. Each one of them is relatively easy to isolate and fix independently, but to do this, you’ll need to understand the shut-down symptoms, so that you can work to correct them.

How To Prevent Your Onan Generator From Shutting Off

  1. Confirm that your oil levels are appropriate. Your generator may experience some significant issues if the oil level is low. You’ll lose power, and your engine will break down if the oil level is too high. Verify the proper levels in your handbook.
  2. Ensure you’re using the correct oil and filters and following the manufacturer’s directions. The oil or filters might bring on your generator’s issues.
  3. Before operating a new generator, it’s crucial to break it in by running the engine for around an hour each day for five days.
  4. Look for issues with the spark plugs. They must be spotless and devoid of deterioration, corrosion, or wear symptoms. It would help if you replaced any that are missing or damaged.
  5. Make that the air filter is adequate. By just replacing your air filter regularly, you may avoid several issues caused by a dirty filter.
  6. Ensure that you are using the appropriate gasoline. To avoid damage and maintain a powerful generator, use high-quality gas.


Several factors My Onan generator keeps turning off. The generator often shuts down unexpectedly. Some of the most common explanations are listed above. Understanding generator problems help you troubleshoot and fix them.


Why Does The Engine On Your Onan Generator Shut Off?

The overheated engine in your generator could be shutting down. If so, you should wait for it to calm before changing the air filter or adding oil. Check your fan belt as well; if it is worn, it needs to be changed.

Why Does The Engine Of The Onan Generator Buzz?

Your oil level may be too low if you hear buzzing or rattling noises. When adding oil, make sure the level is correct.

Why Does The Engine Of The Onan Generator Continually Fail?

There may be several problems with this. If your battery is dead, you’ll need to charge it first, then turn off the generator while the negative connection is connected. It is expected that this will address the problem. You may need to get a new battery if the one you have is rusty or has seen better days.

When I’m Using My Onan Generator, Why Does It Sometimes Turn Off By Itself?

Suppose your generator suddenly shuts off while you are using your appliances. In that case, you may have to look into various potential causes.

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