onan generator starter problems

Onan Generator Starter Problems+Solutions!


You don’t want the power to cut off while you’re on your RV road trip. Hence, you installed the onan generator. But still, it seems to give you a hard time turning it on.

So you might be tensed and want to know how to solve onan generator starter problems?

Well, the problem can be with your power button, maybe you’re turning on the button wrong. So next time, hold the “on” button for 20 seconds and it will start. If not then the battery may have overrun, so just let it rest for 2-3 days. Or the problem can be that there’s not sufficient oil for the motor to operate. Then just add oil to half of the tank. And it will operate smoothly.

Now you’ve seen the trailer, for details,  just read our segment till the end.

Onan Generator Starter Problems With Easy Solutions

There might be several reasons behind your onan generator starter problems. So we tried to list up the most common problems with their solutions. Just scroll down and see for yourself.

Power Issues

We know how stupid it sounds and you’re probably laughing over it. But trust us, buddy, even we’ve faced the power issues just because of the silly mistakes.

You might have thrown away the generator manual right after installing it but skipped some important notes. And that is the reason why your generator is not starting.

Let us tell you what you might be doing wrong. Well, you might be pressing the power button all the way wrong. Now you can think what’s the other way to press the power button so that it actually works. 


Since you’re all confused about how to press the power button. Let’s help you visualize the power button. The button has two ends. And you are used to pressing only the on option once and wait for the generator to start working.

But this isn’t the perfect way to start your onan generator. To start it, you have to press the off button for 7-10 seconds. Then wait for another 10 seconds. Finally, it’s time to press the on button.

You’ve to hold the on button for 20 seconds. But make sure not to hold it for more than 29 seconds. Otherwise, you’ll end up confusing the system. And when you press the button, you’ll hear the generator start operating.

Battery Issues

Your generator still doesn’t work after pressing the power button properly? Then check the generator battery.

But just like any other battery, the generator also has a life span. When you buy the generator, it comes with an expiry date. So it can happen that the expiration date is over.

Or the battery is not working the way it should be.

It is also possible that the battery is not connected to proper power voltage. No matter which one is troubling your generator battery, we’ll help you to solve it. 


So let’s assume that the problem is that the battery got expired. To be sure about it, check for the date on its body. If the date is still visible, you’ll know if it’s already expired or not.

If you can’t find the expiry date, just search for the generator model number. Then call the RV specialists to ask for the expiration date. This way you’ll be clear if it’s actually expired or not.

But if it’s not still expired, then the battery might have overrun. Or you’ve tortured it by putting a lot of pressure on it. So now it’s overheated and stopped working. In this case, you have to let it rest for 2-3 days. Then again try starting the generator. It should work this time.

But if you’re already on a trip and can’t afford to wait that long, just call the RV specialist. If you’re lucky enough to keep the warranty, they will fix or replace the battery. 

Motor Issues

It can also happen that none of the above is the issue with your onan motor-generator. So what else can it be? Well, it can be the motor. We’ve looked into the power button and the battery. Now it’s time to check the motor.

Maybe the motor isn’t running the way it should. And the reason behind it could be the oil level. You’ve seen the oil monitor on the right side of your driving panel. There are green and yellow lights that indicate the oil status.

So check if it shows a low oil level. Because that could be the reason why the generator’s not starting. Let’s look at what you can do then. 


For this, you’ll need to open the oil tank and see the oil level yourself.  Since the oil meters don’t always work properly. If you haven’t used your RV for the last 2-3 days, you need to add more. Even if the oil meter shows a medium oil level.

So see if the oil level is below a quarter or not. If it is then it’s severely low. Even if it’s halfway filled, you need to warm it up by putting in some extra oil.

If the oil tank is quarter filled then add oil until it gets to the halfway point. And if it’s already half-filled, at least add oil so that one inch above the half-line fills up. Now just start the generator and it should work perfectly.


Question: What should be the voltage to run the generator battery?

Answer: Well the voltage to operate the battery perfectly should be 11 volts. It can range from 10-12 volts. But do not set under 10 volts otherwise the battery will be damaged.

Question: Is it normal that my power button doesn’t work on the first try?

Answer: It is completely normal for the power button to not work the first time. It can take up to three attempts to let it work.

Question: How to reset my onan generator?

Answer: To reset your onan generator, you have to turn off the main switch. Wait for 1 minute. And start it again. Then turn on the power button.

Parting Words

By now you know what the onan generator starter problems are and how to solve them. We hope that you’ll be able to put that knowledge to solve it.

For any queries just leave a comment.

Good luck and thank you.

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