Onan Generator Starts Then Shuts Down Troubleshooting Solutions

In power outages, you can’t imagine your life without electricity. Suppose you are on a campsite and enjoying your vacation and suddenly the light goes out. Can you imagine the frustration and tension in this situation? Of course, machines have some mechanical problems that come after their continuous usage and there is nothing to worry about. You can now quickly troubleshoot any mechanical defect in your generator. Or you can take the assistance of some professionals.

Onan Generators are best for use on Campsites. These are also called RV generators but they can also be used in small homes. Onan generator one of the common problems that people face is it starts and then shuts down. But you can’t manage to bear this sudden loss of power and want to know how to troubleshoot this error by yourself. You are at the right place!

In this article, we will discuss the Onan Generator’s starts and shut down error in a simple and easy way. We will also discuss some of the other faulty codes of the Onan Generator.

Onan Generator Starts and then Shut down – Possible Reasons

1. Low Fuel supply

First of all, the main reason for this error is might be the fuel supply is below the level. A low fuel level or no fuel will automatically stop your engine from working. Another explanation for this could be that the fuel you put in it has been sitting there for a while. And the oil in the tank goes stalls or you can say that it becomes more viscous and could be able to reach the motor.

Low Fuel supply

I will recommend you check your fuel supply first and then go for other options. Also, check to see if it has become dirty or not and if the gasoline tank is full. If the fuel is indeed soiled and old, you will need to switch to the new fuel.

2. Faulty Electrical Circuit

Another frequent problem that could cause your generator to stop working immediately after starting is if it has an issue with its electrical circuit. Electric Circuit has its own importance as it transfers current to the generator through the wire. Be attentive when you start your generator.

If you hear some sparkling sound from the circuit or some spark light, then there is definitely a problem with the electric circuit. You will need to use a different way to verify if the problem is electrical.

3. Defective Fuel Cap

Number third is a defective cap that is causing your generator to stop working. This could be an indication of a fuel cap issue. Lift the fuel cap on your generator, then turn it on to verify this.

If you watch it for a while and it resolves the issue, your fuel cap may be defective. You will have to buy a new fuel cap and replace the old one in order to solve the problem because the fuel cap cannot be fixed. Your generator should now operate without automatically shutting off after you have correctly replaced the fuel cap.

4. Worn-out Armature Coil

Everything degrades over time so there might be chances that your generator’s armature coil is not working properly or is defective. The armature coil is also one of the reasons that your generator stops after starting. This is when the generator doesn’t emit warning noises when an electricity-related issue arises. Check to see if the fault is electrical before proceeding.

Pick up a meter, and fasten it to your generator. Your generator’s armature coil may occasionally become worn out and malfunction. Due to this, it won’t generate enough sparks to keep your device functioning properly. To determine whether the coil is the issue, pay attention to it.

Worn-out Armature Coil

Remember that the armature coil needs time to cool down if it is the source of the issue. The coil will struggle to produce sparks when it’s heated. Wait for the coil to cool entirely, which should take 30 to 40 minutes.

Start your generator once more after that to see if the issue was resolved. If this does not resolve your problem, you should have the defective armature coil replaced with a new one. This is simple to find and replace this component.

Onan generator only runs holding the start button – Troubleshoot

In this article, we will discuss some of the most common errors that people face. So reasons why Onan Generator only runs holding the start button or it stops as you release the start button will be discussed here.

1. Low Voltage

When the start button on the generator dies as soon as it is pressed, there is no longer any output from the machine. You can use a voltmeter to check if the current is passing or not from the generator. Sometimes this issue is faced by many people as the voltage level is low and the generator can’t get enough of the current to run.

It is recommended to look for any cables that may have unintentionally been disconnected if there are none. The issue you’re experiencing can easily be resolved by reinserting them. It’s important to remember that checking the current on a generator might be hazardous.

It is advised that you seek expert assistance if you have problems like this for this reason.

2. Damaged Stators

If the issue continues, your generator’s components have probably suffered damage. It can be challenging to identify what might be the problem’s root.

But fortunately, they have provided an Onan Generator Troubleshooting Guide and codes that will help you a lot in finding the root cause. They have elaborately described each and every component of the generator and also the solution to problems.

Damaged Stators

It will take a lot of effort to go through the list, but it will be worth it once you identify the precise damaged component. Then you can get a replacement for it from a shop close by.

Onan is a proud company that offers its customers every possible type of generator replacement part. So, you can avail of their offer too.

3. Damaged Starter Switch

After checking the voltage and stators if the still problem persists, then check the switch of the stator. There are chances that it has been damaged. However, a workshop may also quickly fix or replace it.

You should be aware that the switch getting destroyed is very unlikely to be the cause of this issue. Because of this, it is advised that you check all the components and fuel levels on your Onan generator before proceeding with taking it to a repair.

Onan Generator Troubleshooting Codes

According to the Onan manual resources, the troubleshooting codes are as follows;

  • Low Oil Pressure Fault—Code No. 2
  • Service Check Fault—Code No. 3
  • Overcrank Fault—Code No. 4
  • Overvoltage Fault—Code No. 12
  • Over Frequency Fault—Code No. 14
  • Under Frequency Fault—Code No. 15
  • Governor Actuator Fault—Code No. 19
  • Governor Actuator Overload Fault—Code No. 22
  • Low Oil Pressure Cutoff Switch Fault—Code No. 23
  • Voltage Sense Fault—Code No. 27
  • High Battery Voltage Fault—Code No. 29
  • Overspeed Fault—Code No. 31
  • Low Cranking Speed Fault—Code No. 32
  • Control Card Failure Fault—Code No. 35
  • Engine Stopped Fault—Code No. 36
  • Invalid Genset Configuration Fault—Code No. 37
  • Overcurrent (Field Overload) Fault—Code No. 38
  • Generator Rotor Fault—Code No. 41
  • Processor Fault—Code No. 42
  • Processor Fault—Code No. 43
  • Speed Sense Fault—Code No. 45
  • Ignition Fault—Code No. 47
  • Generator Field Sense Fault—Code No. 48
  • Processor Fault—Code No. 51
  • Fuel Injector Fault—Code No. 52
  • Mat Sender Fault—Code No. 54
  • Map Sender Fault—Code No. 56
  • Overprime Fault—Code No. 57

Onan Generator 4000 – Troubleshooting

As we know that these RV Onan generators are not so heavy as compared to the whole house or another portable generator. These generators have very limited power storing capacity. But you can say that Onan Microquite 4000 generator is the best choice for camping as they are very durable and have good power capacity.

Onan Generator 4000 - Troubleshooting

In this article, we will discuss some of the problems of this generator and how you can troubleshoot them with our experts’ advice.

1. Generator shuts off

Every machine needs maintenance so is the case with this generator. The more you maintain it the more it will last. So, it’s up to you if you want to invest in these generators their upkeep is compulsory.

Dirt and dust usually get into the generator’s pipelines and tank and cause the fuel to get dirty and viscous which in turn damage the generator further. So keep the generator away from dust and debris.

You must therefore clean your gadget in order to stop this issue. However, you should be aware that if you are a total beginner, this technique can also be highly risky. You can either search online for guides to assist you in this situation. Or it is recommended to take the help of some professional to avoid any mess.

Before you deal with any electrical equipment make sure that you have turned off the appliance whether it’s a generator or any other device. In addition, use a mixture of seafoam and gas to thoroughly clean the tank, by doing this the amount of damage in pipes can be measured. A professional will recommend you replace the pipes if they are bent or broken. However, if they only contain a small amount of dirt, you can quickly clear it off.

The low-fuel sensor is very active in Onan Generators. They automatically stop working if the fuel is below a certain level. So, make sure the amount of fuel is maintained in the tank.

2. Electrical Issues

People have complained about electrical issues in Onan Microquite 4000 so, it should be considered a matter of concern. This covers issues that may stem from the internal hardware as well as issues with the cables or connectors.

Dealing with this matter is not so easy. I would recommend you consult some professional for this matter. The hardware is usually damaged in this case and it needs some technical expertise to get resolved. Workshop experts will examine it and repair any component that might be the source of the issue.

Electrical Issues

On the top of your unit, there are four major screws that must first be removed in case you have decided to do it on your own. Then, you may check out all the components of the generator. Your generator’s starter is typically the most problematic part. You can check it out using a voltmeter and record the current numbers.

3. Battery check

The next step, after checking all the parts of the generator and ensuring that none of the parts is problematic, check for the battery. The connection can be verified using a voltmeter in the same manner as before.

If, however, you observe that no current is passing through the cables, your battery is probably having issues. The majority of problems can be fixed by thoroughly cleaning the apparatus and filling it with water. In rare circumstances, people may even need to buy a new battery for their car.

How to reset the Onan generator?

  1. Onan generator has to be reset if you observe error codes. You can reset your Onan Generator by following the steps we have designed for you. Error Code 36 is also one of the codes faced by many people so if you encounter Onan generator Code 36, you must perform any of the aforementioned changes before attempting again.
  2. On your generator, find the priming button. It is located on the side of the machine, underneath the gas tank. Additionally, it serves as the generator’s start and stops button.
  3. For at least 30 seconds, keep pressing the prime button.
  4. To start your generator, turn the switch to the “off” position.
  5. Check to see if the problem code has disappeared after 15 minutes of running your generator. When the trouble code persists,

Onan Generator Starts then Shuts down – FAQs

Why does my generator start and then shut off?
There are be 3 problems if your generator starts and then shuts off. These are as follows; ● Low Voltage ● Damaged Stators ● Damaged stator Switch
Why the Onan generator is keep shutting off?
People who face this issue must check the following things in the generator; ● Battery ● Electrical issues ● Voltage issue
What is Code 27 on an Onan generator?
Code 27 on the Onan generator is Voltage Sense Fault. People who face this issue can take guidance from the codes available in the user manual.



To conclude, I must say that many parts of contemporary generators have a high failure rate. Error codes are provided by the makers for this reason. You can typically locate the problem with these codes, and then look up solutions in the manual.

Sadly, this is not always the case, and in order to identify the real cause of the issue, you must look outside of the handbook. You’ll save time and effort by being prepared. You can also end up saving a lot of money.

In general, error codes are beneficial, but they can also lead you astray.

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