My John Deere Won’t Start With A New Battery – Why? What To Do?

You just replaced your John Deere battery, but your appliance won't start. It only keeps cranking up. Why is this happening? We researched and found the answer to help you solve the problem.

Your John Deere could fail to start after installing a new battery for two main reasons: no fuel or no spark. So, check if the spark plugs are wet or dry to determine if you have a fuel or spark problem.

To fix your John Deere, you need to know more than finding out the root of the problem. This post provides a helpful guide for you to solve the problem. Also, there are several other reasons why your John Deere might fail to work even with a new battery. Read on to learn more!

Why Does My John Deere Not Start With A New Battery?

John Deere lawn mower in front of modest home

If your John Deere starts to malfunction after you replace its battery with a new one, chances are you have a faulty spark plug or no fuel. Often, the new battery is rarely at fault. 

To identify the issue your John Deere has, remove the spark plugs and check if they're wet or dry. If the spark plugs are wet, you have faulty sparks. But if they're dry, you have no fuel.

Find the fuel-shutoff solenoid at the bottom carburetor. Listen for a click when you turn it on and off again. Then, pull the rubber hose from the fuel pump and turn over the engine. Check whether fuel shoots out of the hose with each engine revolution. 

Your John Deere could also have a bad ignition switch if the spark is missing. So, consider replacing the ignition switch to avoid start-up issues.

Dirt and damage can cause a bad spark plug or loose connection. Dirt will likely collect if you don't regularly clean your John Deere parts.

Remove the spark plugs and look for signs of dirt, debris, carbon buildup, or a cracked insulator. If the spark plug is in good condition, with no damage or heavy buildup, clean the tip with a wire brush. You don't need to replace it.

However, it is best to replace a damaged spark plug. Remember to follow the instructions provided in your user's manual when doing this.

Check out this spark plug on Amazon.

How To Troubleshoot Your John Deere

Here are three simple steps to troubleshoot your John Deere that won't start with a new battery:

Step 1 - Clean Dirty Wires

A new battery with dirty connections won't work. For this reason, clean the wires and use sandpaper to clean the battery posts.

Step 2 - Tighten Loose Bolts And Terminals

Your John Deere engine vibrates a lot and with high intensity. This vibration can loosen the bolts and terminals. Therefore, tighten any loose bolts and adjust the wrenches regularly.

Step 3 - Check The Starter, Solenoid, And Relay

Inspect the starter, solenoid, and relay for any issues. You can use a voltmeter to the voltage reading while turning it over.

Other Reasons Why Your John Deere May Fail To Start Even After Replacing The Battery

Agricultural Equipment Mechanic working on an antique John Deere tractor

If your John Deere is having start-up issues despite replacing it with a new battery, it probably has another problem. Your John Deere comprises many different parts, and ensuring the condition of these parts is key to having a functional mower.

If one part is in bad shape, it will cause your John Deere to have start-up issues. Read on to identify why your John Deere may fail to start and how to fix it.

Faulty Fuel Cap

A faulty fuel cap creates a vacuum in your John Deere. The vacuum prevents fuel from leaving the tank, which is why your John Deere won't start.

To identify a faulty fuel cap, try removing it and see if your machine runs fine. Then, put the cap back on again and check whether the mower keeps running.

If your mower acts up and shuts off after some time, it's broken. Fix this issue by replacing the old cap with a new one.

Bad Or Old Fuel

Fuel left unused for a long time, say 30 days, will become stale. You'd want to avoid this because the ethanol attracts moisture to the fuel. This moisture will evaporate and clog the fuel system.

You can use a fuel additive to stabilize the old fuel, thus keeping it from becoming stale. Alternatively, you can use up all the fuel to avoid having issues.

Blocked Fuel Filter

This issue is related to having bad fuel. The fuel filter can become clogged if it's running old fuel that has started breaking down.

If your John Deere won't start because of a blocked fuel filter, replace the filter with a new one and regularly change or stabilize your fuel.

Dirty Carburetor

The carburetor regulates the fuel-to-air mixture that creates combustion. So, a dirty or clogged carburetor may cause your John Deere to stop working.

Regularly inspect and clean your carburetor with a carburetor cleaner. You may need to repair or replace it if it's severely damaged.

Faulty Safety Switch

Safety switches operate in the control system to keep users safe when using the mower - they are designed to kill the engine when needed. A faulty safety switch can cause John Deere start-up issues. 

Use a multimeter to identify a faulty safety switch. It's important to fix this issue immediately to avoid any injury or accident while using the mower.

Clogged Air Filter

A clean air filter is vital to maintaining your John Deere's functionality. When the air filter is clogged, the dirt buildup will prevent the air from getting in, causing your John Deere to have start-up issues.

It's important to fix this issue immediately to prevent further damage. Replace your air filter every year or when severely impaired. 

Bad Ignition Switch

A faulty ignition switch could be why your John Deere isn't starting. To identify a bad ignition switch, use a multimeter. Start your John Deere mower and see if anything happens.

If your ignition switch is faulty, replace it.

Faulty Ignition Coil

A bad ignition coil could mean the voltage isn't delivered to the spark plug. When this happens, your engine won't fire and start up.

To identify a bad ignition coil, check the continuity using an ohmmeter. If you find that it's in bad shape, replace it.

Check out this ignition coil on Amazon.

How Do I Maintain My John Deere Mower?

A male worker using a ride on lawn mower John Deere X540 in a park.

Regular inspection and maintenance is the key to keeping your John Deere functioning well. Here's how to do it:


  • Sharpen the blades of your mower
  • Inspect the tires
  • Clean the underside of your John Deere
  • Replace your spark plugs yearly (or every 100 hours of usage)
  • Grease the machine's fittings
  • Drain and replace the mower's oil every 25-50 hours of use

Is It Possible To Jumpstart A John Deere With A Car?

Green lawn mower tractor. Cutting the grass with the lawn mower close up.

You can jump-start your John Deere with a car. Ensure that you use a 12-voltage battery for the exercise; you shouldn't jump-start mowers with a 6-voltage battery.

In Conclusion

Your John Deere is prone to dirt buildup and clogging. It's important to regularly inspect and clean your machine to get rid of any dirt buildup. Even if you replace your John Deere with a new battery, it won't function properly if the root of the problem is not solved.

Do simple troubleshooting and find out what's bugging your mower. It could be the carburetor, the filters, or a combination of different issues. Inspect your mower and follow the tips provided to fix it!

If you enjoyed reading this post, you could check out these related topics: 

Lawn Mower Blowing White Smoke - What To Do?

Should You Edge Your Lawn Or Mow First? [What You Need To Know]

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