How to Reset Your Onan RV Generator (Easy Guide)

If your Onan RV generator keeps shutting off, it may be time to reset it. However, resetting the generator is something that confuses many new RV owners. If you are one of those people, then keep reading this article below as we take you through how you can reset an Onan RV generator.

To reset the generator, simply turn off the breaker. Next, press the stop button twice, then quickly press the start button. Hold the stop button down as you wait for a red light. Repeat the procedure if it still does not turn on.

Let’s study a little bit about the Onan RV generator before delving further into the instructions.


What Is an Onan RV Generator?

Onan generators, which are made by Cummins Inc., are mobile power sources for your RV. Your motorhome may be powered by a trustworthy Onan RV generator.

Onan generators that operate on gasoline, diesel, or liquid propane are available. The majority of common recreational vehicles are powered by either gasoline or propane. Diesel generators are used by heavy-duty vehicles, farm equipment, buses, and huge coaches.

Onan generators often fuel compact, medium, and large RVs and are securely integrated into RVs. Onan has a generator to suit every size motorhome camper, ranging from the little QG 2800i to the big split-phase QD 12500, as well as a portable unit.

Overview of Onan RV Generator

In response to a friend’s suggestion, David Onan created the first Onan generator in 1926. It has changed over time to become what it is now. Many RVs have Onan RV generators permanently mounted. Compared to their earlier predecessors, they are lighter, quieter, simpler to mount, and more fuel-efficient.

Onan power systems were designed with larger oil storage and are typically lightweight. As a result, there are fewer issues and longer gaps between repairs. The reduced weights enable RVers to carry more cargo.

Upwards of 85% of the market for RV generators is controlled by Onan. They offer a high-quality product that lasts for decades and delivers on its promise to drive recreational vehicles of all sizes and shapes.

Benefits of an Onan RV Generator

Onan has a reputation for reliability. If you buy an RV with one of these generators already installed, there’s a good chance that, with regular maintenance, the generator will outlive the RV.

A handy power supply that doesn’t get in the way is what most RVers desire. They activate with the simple flip of a switch, are far quieter than in previous years, and consume significantly less gasoline. It may be initiated remotely and swiftly recharges batteries due to its integrated generation in the RV.

Permanent Magnet Alternators (PMA), which rely on the magnetic field of the rotor to create power, are among Onan’s most recent developments. Because it may slow down the engine, this reduces disturbances and keeps the generator silent. It also reduces fuel consumption.

Drawbacks of an Onan RV Generator

Because the RV has a built-in generator, any required maintenance must be done there. A portable machine that may be fixed anywhere may have this as a disadvantage.

Being built-in also implies that the location and noise level will never change. For the owners’ comfort, a portable unit can be placed farther from the RV.

Another disadvantage of these generators is their price. Onan RV power system with wattages between 2500 and 5500 watts can cost between $3,100 and $4,600. However, the cost of installing a generator on an old setup is quite high. Many recreational vehicles already have it installed.

These generators are frequently a little loud as well. Always remember to be respectful and observe quiet hours to prevent upsetting your neighbors.

These are excellent generators when maintained correctly, but issues may develop if left unattended.

Resetting an Onan RV Generator

To reset the Onan RV generator, follow the below steps:

1. Switch off the generator’s breakers

2. Quickly press STOP twice on the generator before quickly pressing START. Never turn on the generator.

3. Keep pressing Stop/Prime, and a consistent red light should appear. If not, repeat the previous sentence.

4. Start the generator as normal if the stop/prime signal is continuously red. Switch on the breakers after it has stabilized.

5. Press and hold the primer button for around 30 seconds to erase a fault code. Release the button once that time has passed, then restart the system.

6. Once the code has been cleaned, let the generator run for roughly 15 minutes. To find out what steps you need to take, consult the user guide for your particular model. Each generator is created differently.

If none of these approaches succeed, consult a friend or mechanic who is familiar with resetting generators.

Resetting the Onan Circuit Breaker

The methods listed below should be used to reset the Onan circuit breaker. You can also find detailed instructions in the video below:

Step 1: Find Your Onan

It has a black access panel and is inside a green container. It will either be dangling beneath in the middle of the back of your RV or from behind an access door. Making two ramps out of 2×8 planks will give you a little more working space if your Onan is beneath.

Step 2: Take the Access Cover Off

To detach the access cover, insert a finger into each of the hinges, lift up, and pull out. Keep in mind that the hinges are at the end of the cover when you attempt to replace it.

Step 3: Find the Circuit Breaker

The small lever could be hard to notice; however, if you know where to reach for it, you can easily locate it. Once the access door is removed, you will find the following: On the edge of the control panel, towards the left of the fuel filter and beneath the 5 amp DC fuse, is the 25 amp AC circuit breaker.

Step 4: Reset the Circuit Breaker

The downward side is off, whereas the upward side is on. Keep it upward while resetting by flicking it in the opposite direction and then back; don’t worry too much about the positioning.

Step 5: Change the Access Cover

Keep in mind that the hinges are at the bottom. Ensure that it is properly fastened. They must be installed to operate the generator for much more than a quick test because they are costly to replace.

Onan Generator Troubleshooting Guide

Three of the most frequent Onan generator issues are described here, along with solutions.

1. An Overheated Generator

Onan generator overheating is one of the most frequent issues that users encounter. Since your gadget will shut down when you are using it, dealing with this may be pretty frustrating. However, you must be aware that a big machine like this is susceptible to overheating. 

This company has created several small-scale designs that you can place anywhere.

But you have to put a big generator like this in an adequately ventilated position. This is crucial since the gadget has to make contact with something when it is subjected to pressure. Knowing this, moving your generator will enable you to resolve the issue you were experiencing.

If you do not have a suitable location to place this gadget, though, installing a new fan next to your generator is another solution you might try. However, bear in mind that in order to keep the generator cold, it must be turned on at all times. 

Lastly, keep in mind to add coolant to your gadget if it begins to run low on it in addition to all of this. You won’t encounter the exact issue again by following these instructions.

2. The Generator Is Running Yet There Is No Power

Another frequent problem with Onan generators is that there is no electricity even when they are functioning. Your generator may have a defective component, but it may take some time to identify it.

This is why you should examine all of the wirings for your gadget as the first and simplest remedy. Occasionally, if you were attempting to move the generator, they may come off. After making sure that every connection is secure, check the cables. The cable may be damaged if you notice any creases or folds in them. Getting rid of the problem should be made easier by replacing them with fresh ones.

Next time, take more care when routing the cables because they are easily damaged by sharp curves. You will need to inspect each moving item individually if the generator is still not operating. Using the handbook that Onan has supplied will save you significant time and work. This includes tests that will make it easier for you to locate the problematic component.

3. The Generator Does Not Start

You could likely encounter your generator not turning on when you attempt to start it. The majority of individuals always check their fuel level first. Nevertheless, even if there is still fuel, your generator does not need to start using it.

The minimum fuel demand for most Onan generators is roughly one-fourth of the tank. The generator may abruptly stop operating when the fuel level drops below it. To ensure a smooth ride, ensure your gasoline is constantly above a certain level.

Why Does My Onan Generator Constantly Shut Off?

Even high-quality equipment sometimes fails. Even the greatest of them are subject to this potential. It is a fact of life that there are things that need to be fixed because they have a defect in their design.

Your Onan generator won’t start for at least 15 reasons—everything from a faulty ignition coil to low gasoline or oil to a fuel leak. Pick one and work your way through the list one at a time until the issue is resolved.

Insufficient Oil

This is how they are intended to function. Whenever the device detects a low oil level, it will often turn itself off. This safeguard prevents you from unintentionally damaging your Onan 5500. Simply remember to check the oil frequently.

Insufficient Fuel

Once more, the generator is programmed to turn itself off when the fuel level falls below 1/4 of a tank. It serves as a safeguard to keep both you and the computer secure. Your only option in this situation is to replenish the gasoline tank, which is a relatively simple process.

Old Gas

Onan generators don’t use diesel fuel; they run on gas. If the gas has been sitting in the tank for a while, it may go bad or get stale. The generator won’t start if it occurs. To get it back to operating, change the gas.

Blocked Carb

In this case, the machine is either not receiving enough fuel or the air-to-fuel ratio is poor. The cause of the obstruction is variable and has several potential origins. To fix the issue, clean the carburetor.

Blocked Air Filter

The generator requires a reliable air supply to operate properly, much like the carburetor. The generator will shut off if the air filter is blocked because too little air enters the engine. To avoid this, clean or change the air filter.

Bad Spark Plugs

This issue could not entirely be due to the previously mentioned sources. The spark plugs can be one source of this. The generator has trouble running if it starts to malfunction. Simply re-gap, wipe or change the spark plug.

Overloaded Generator

The generator itself may be the next potential source. When pressed to provide more power than they are capable of, these machines are programmed by advanced technology to shut down. In this situation, your best option is to reduce the electrical load and reboot the generator.

Control Board

You must also examine the control board to determine whether it is malfunctioning or displaying an error code that indicates the issue. It’s also possible that the device isn’t receiving enough electricity. Check to determine if a magnetic field is being produced by the generator.

If you lack the necessary equipment, expertise, or understanding of how the generator operates, leave this sort of job to specialists.

Last Words

This article offers a thorough tutorial on how to restart an Onan RV generator and solve some of the most frequent issues that they encounter. We hope that the instructions in this article will prove useful to you.