How to Jumpstart an Onan RV Generator: Expert Guide

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Are you excited about your next RV adventure, but suddenly faced with the frustration of a dead Onan RV generator battery? 

I know your Onan RV generator serves as a reliable power source, providing electricity to various appliances and amenities in your motorhome. 

That’s from running your air conditioner and refrigerator to charging your devices, a working generator keeps your RV experience comfortable and enjoyable.

But will you allow a depleted battery to spoil your trip? 

I guess not! 

But what way out, what are you going to do? Jumpstart it? 

That’s a good idea. 

When it comes to understanding how to jump-start your RV generator, it can save the day and keep your journey on track. 

Hence, in this article, we’ll guide you through the step-by-step process of jump-starting your Onan RV generator safely and efficiently.

Trouble with your generator? Get expert personalized troubleshooting tips tailored for you alone directly to your email. Contact us now for reliable support and practical solutions. Let’s fix it together – reach out today!

Why Jumpstarting Your Onan RV Generator? Is it Necessary?

When you’re far away from the city, and couldn’t find a means to charge your battery or change one to start your RV Onan generator, jumpstarting your generator is necessary.

Dead batteries are usually the most common issues you might face as a RVer when it comes to your generator which is why you need to learn how to jumpstart the generator. 

A lot of things might contribute to your battery dying among which include:

  • Prolonged storage without charging.
  • Infrequently used.
  • Or even extreme temperatures.

However, you have to worry, you can always change the battery and your generator will be starting normally. 

But before changing your battery, I know you will still need it running. 

Hence, with a little know-how and the right tools, you can quickly revive your generator and get back to your adventures.

Also Read:- How to Remove an Onan Generator from an RV in 3 Simple Ways + Video

So, How Can You Jumpstart Your Onan RV Generator?

1. Take Safety Precautions

As with any task involving electrical components, safety must always come first. Before you attempt to jumpstart your Onan generator, make sure you take these safety precautions:

  • Put on personal safety gear, such as gloves and goggles, to protect yourself from any potential hazards.
  • Park your RV in a well-ventilated area, as generator fumes can be harmful if not properly ventilated.
  • Position your generator in a location that allows easy access to the battery terminals.
  • Turn off all electrical loads and appliances connected to the generator to avoid any mishaps.

After you have taken the safety precautions, you move to the next step.

2. Identify the Battery

Now that you’ve ensured your safety, it’s time to locate the generator’s battery. In most cases, the battery can be found in a compartment near the generator unit. 

Once you’ve located the battery, make sure to;

  • Check its health. 
  • Look for signs of damage, corrosion, or leaks. 
  • Check the battery connections.
  • Check the battery voltage, etc.

If you have checked and found out the battery appears to be in poor condition that’s leaking and is not in good health, jumping it might not be safe, and you should consider replacing it.

3. Gather the Necessary Tools

If you have checked the battery and found out it’s healthy — save for jumpstarting, you’ll need the following tools:

  • A set of jumper cables (also known as jump-start cables). 
  • Another running vehicle with a compatible battery or an auxiliary battery.
  • Cleaning supplies, like a wire brush, baking soda, and water, to clean the battery terminals if needed.

4. Prepare the Helper Vehicle

If you have access to another running vehicle, you can use it as a helper vehicle to jumpstart your generator. 

Follow these steps to prepare the helper vehicle:

  • Park the helper vehicle close to your RV, ensuring there’s enough space between the two.
  • Turn off the engine and all electricals in the helper vehicle to avoid any power surges. 

However, if you can’t find a helper vehicle around, you can make use of your solar panel if you got one or learn how to troubleshoot an Onan generator that won’t start

5. Connect the Jumper Cables

Jumpstart a generator,

Now, let’s get into the actual jumpstarting process. Follow these steps carefully to ensure a successful jumpstart:

  1. Connect the red positive (+) clamp on one end of the jumper cable set to the positive (+) post of the vehicle battery.
  2. Connect the red positive (+) clamp on the other end of the jumper cable set to the positive (+) post of the Onan generator unit’s battery.
  3. Connect the black negative (-) clamp on one end of the jumper cable set to the negative (-) post of the helper vehicle’s battery.
  4. Connect the other black negative (-) clamp to a clean, unpainted metal surface on the RV. This serves as the grounding point for the jumpstart.

Note: Make sure all the connections are secure and the clamps have a tight grip on the battery terminals. Also, know that the red clamp signifies the positive terminal. Which should firmly grip each of the terminals.

6. Charge the RV Generator Battery

After the cables are securely connected, allow the vehicles to sit for a few minutes. This will enable the dead battery to charge slightly before attempting to start the generator. After a brief waiting period, rev the engine of the helper vehicle to add some charge to the dead battery.

7. Perform Safety Checks

Once the generator has started successfully, it’s time to perform some safety checks before disconnecting the jumper cables. 

Follow these steps by carefully disconnecting the jumper cables in the reverse order of connection:

  • Remove the black negative (-) clamp from the RV’s metal surface.
  • Disconnect the black negative (-) clamp from the helper vehicle’s battery.
  • Disconnect the red positive (+) clamp from the Onan generator’s battery.
  • Finally, remove the red positive (+) clamp from the helper vehicle’s battery.

Remember, safety is essential throughout this process, so handle the cables with care to avoid any electrical mishaps.

8. Verify the Generator’s Functionality

After disconnecting the jumper cables, perform a quick check to ensure your generator is working correctly. 

Turn on some appliances in your RV to confirm that the generator is supplying power as expected. 

If everything is functioning well, congratulations! You’ve successfully jumpstarted your Onan RV generator.

What to Do If Jump-Starting Fails?

In some instances, jump-starting may not be successful. If this happens, don’t worry; there could be an underlying issue with the generator or the battery. To troubleshoot the problem, consider the following steps:

  • Assess the Situation: Double-check all connections and ensure the jumper cables are correctly attached. If everything seems fine, there may be a deeper issue with the generator that requires professional attention.
  • Seek Professional Assistance: If jump-starting repeatedly fails, it’s best to seek help from a qualified RV technician or mechanic who can diagnose and resolve the problem efficiently.

Maintenance Tips for Onan RV Generators

To avoid future generator battery issues and ensure a seamless power supply during your travels, follow these maintenance tips:

1. Regularly Test the Battery: Perform regular battery tests to check its health and charge level. Address any issues promptly to avoid unexpected breakdowns.

2. Keep the Battery Clean: Clean the battery terminals regularly using a wire brush, baking soda, and water to remove any corrosion or dirt that may affect performance.

3. Follow Professional Maintenance Schedules: Stick to the manufacturer’s recommended maintenance schedules for your Onan RV generator. Regular servicing by professionals will keep your generator in top shape.

Final Thought 

Jump Starting your Onan RV generator may seem daunting at first — that’s how it has always been. But overtime when you are armed with the right knowledge and precautions, it will be a straightforward process for you. 

So, the next time you encounter a dead generator battery, don’t panic. With this step-by-step guide, you’ll be well-equipped to jumpstart your Onan RV generator and get back on the road in no time.

Frequently Asked Questions

1. Can you jumpstart a generator?

Yes, you can jumpstart a generator using an external power source like another running vehicle with jumper cables. The electricity provided by the external power source can power the generator and revive a dead battery.

2. Does an RV generator charge the battery?

Yes, an RV generator not only charges the battery but also serves as a direct power source for various 120-volt electrical appliances in your RV, such as the air conditioner, furnace, TV, and water heater.

3. How does an Onan generator work?

An Onan generator in an RV uses the coach battery to start and then operates using the RV’s fuel system. The generator draws power from the coach battery initially and then uses fuel to generate electricity to power the RV’s electrical appliances.

4. Can you jump-start an RV battery?

Yes, you can jumpstart an RV battery, whether it’s the coach battery or the generator battery. Just make sure to follow safety precautions and use the appropriate jumper cables and another running vehicle or auxiliary battery.

5. What should I do if I see corrosion around the battery terminals?

If you notice corrosion around the battery terminals, it’s essential to clean it before attempting to jumpstart the battery. Use a wire brush, baking soda, and water to clean the terminals thoroughly. Corrosion can hinder electrical connections and affect the jumpstart process.


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