Lawn Mower Blows Fuse When Starting: 9 Major Causes With Easy Fixes

Encountering a blown fuse while starting your lawn mower can be a frustrating experience.

If your lawn mower blows fuse when starting, then it may cause serious problem in the long run. That’s why you must be aware how to fix this issue as soon as possible.

This article delves into the possible reasons behind such occurrences, providing valuable insights to help troubleshoot and prevent future fuse-related issues.

Equip yourself with the knowledge to maintain your lawn mower and avoid unnecessary downtime, ensuring a smooth, uninterrupted lawn care experience.

Lawn mower blows fuse when starting

Let’s explore the causes, the solutions, and everything regarding your lawn mower’s pesky fuse problems.

Lawn mower blows fuse when starting

Typically, a lawn mower blows a fuse when starting due to electrical issues such as short circuits, damaged wiring, faulty switches, or a malfunctioning solenoid. Often, a worn-out or corroded fuse could also be the primary culprit.

To address these issues, it is essential to regularly inspect and maintain electrical components, replacing them when necessary. A proper understanding of your lawn mower’s electrical system can save you time and money, ensuring your equipment’s longevity and optimal performance.

Causes of Blown Fuses in Lawn Mowers

Blown fuses during start-up are typically due to some form of electrical imbalance. Here are the most common causes:

  • Short Circuits: A short circuit occurs when live electrical wires touch one another, which leads to high current flow and often blows a fuse.
  • Damaged Electrical Components: Faulty switches, malfunctioning solenoids, or damaged wiring can cause an unexpected current surge, resulting in a blown fuse.
  • Old or Corroded Fuses: Fuses are not meant to last forever. Over time, they erode and may not work accurately, blow, or trip.
  • Electrical Overloads: Your mower may encounter an electrical overload when it faces more strain than it can handle, leading to a blown fuse. This usually occurs when your lawn mower’s motor or starter system is confronted with a jammed blade or a stuck pull cord. Trying to mow excessively dense or wet grass, which calls for more power from the motor, can trigger an overload, too.
  • Faulty Ignition Switch: A mower’s ignition switch makes the electrical connection between the battery and the engine’s starter. A faulty ignition switch can cause a higher current draw than usual, making motor startup challenging and eventually causing the fuse to blow.
  • Alternator Stator Problems: An alternator stator in a lawn mower is part of its charging system. If the stator winds, it burns out or short circuits, it could enable a surge in electrical flow, leading to a blown fuse.
  • Voltage Regulator Shorts: A mower’s voltage regulator controls the voltage sent to the battery from the alternator stator. If it shorts out, an ‘overcharge’ situation may occur, causing a surge to the electrical system and blowing the fuse.

Recognizing these causes and taking corrective action can help prolong the life of your lawn mower’s electrical system and ensure a smoother gardening experience. Remember, if you cannot identify or handle the problem, it’s best to call a professional technician or electrician for help.

Solutions For The Causes of Blown Fuses in Lawn Mowers

Given the mentioned causes, here are specific solutions for each:

  1. Short Circuits: The main way to tackle short circuits is by thoroughly inspecting the wiring throughout your lawn mower. Using a multimeter can help detect the presence of a short. Once found, replace the damaged wires promptly.
  2. Damaged Electrical Components: Regularly inspect components like switches or solenoids for signs of wear, corrosion, or damage. If you discover faulty components, replace them immediately.
  3. Old or Corroded Fuses: Regularly checking your fuses can prevent this issue. If you notice a corroded or old fuse during inspection, replace it immediately.
  4. Electrical Overloads: To avoid overloads, make sure you are using your mower correctly. Don’t try to mow very dense or wet grass, as this puts excessive strain on the motor. Regularly check and clean your blades, ensuring they can rotate freely.
  5. Faulty Ignition Switch: A faulty ignition switch can often be identified through unreliable starting behaviours. If you suspect a bad ignition switch, consider replacing it or calling professional help.
  6. Alternator Stator Problems: A professional should address inspected alternator stator issues, as correcting these problems often requires specific knowledge and skills. Regular service appointments can help spot these issues early.
  7. Voltage Regulator Shorts: Much like alternator stator problems, a professional best solves voltage regulator issues. If your mower’s engine runs irregularly or if you notice a recurring blown fuse, a shorted voltage regulator could be the issue. Contact a professional to examine and potentially replace the regulator.

Remember, preventative maintenance always goes a long way towards prolonging the life of your mower. Regularly caring for your equipment and fixing problems soon after they appear can save you significant time and money in the long run.

Prevention is Better Than Cure

Regularly servicing and maintaining your lawn mower will help avoid fuse-related problems and extend your mower’s lifespan. Before starting the mower, always inspect the electrical system, especially the fuses and wiring. This preventative measure could save you a lot of time and frustration.

Understanding these basic but integral components of your lawn mower will ensure you’re never caught out with a blown fuse and are always ready to maintain your garden’s beautiful aesthetics.

Mower blows fuse when PTO engaged

When a mower blows a fuse when the PTO (Power Take-Off) is engaged, it might be caused by various issues. Here are the potential causes:

Mower blows fuse when PTO engaged
Mower blows fuse
  1. A damaged relay switch near the motor that controls the PTO.
  2. Damaged PTO clutch.
  3. Short circuits in the wiring between the PTO switch and the clutch.
  4. Clutch drawing excessive current.

Here are some suggested fixes based on those sources:

  1. Inspect the relay switch for any signs of damage. If damaged, replace the switch and the fuse.
  2. Check the PTO clutch for damage and replace it if necessary.
  3. Inspect the wiring between the PTO switch and the clutch. Look for any frayed wires, damaged insulation, or other visible problems. Fix or replace the affected wires.
  4. If the PTO clutch is drawing excessive current, it might be faulty and need to be replaced.

Remember that working with electrical components can be dangerous if you’re not experienced, so if you’re unsure how to proceed, it’s best to call a professional to help diagnose and fix the issue.

What Causes Fuse Blowing on Cub Cadet Mowers?

Blowing fuses in Cub Cadet mowers can be attributed to several factors:

What Causes Fuse Blowing on Cub Cadet Mowers
  1. Short Circuits: A short circuit happens if live electrical wires touch each other. This generates high electricity flow, which often leads to a blown fuse.
  2. Faulty PTO Clutch: A problematic PTO (Power Take-Off) clutch might draw excessive electrical current, causing a fuse to blow.
  3. Damaged Wiring/Wire Connections: Worn or damaged wiring might cause random shorts that blow the fuse.
  4. Aged or Faulty Fuses: Over time, fuses can wear out, corrode, or become unreliable. This could cause them to blow or trip even under normal electrical load.

Honda Lawn Mower Blows Fuse When Starting

Malfunctioning Starter Solenoid

A solenoid is an electromagnetic coil that acts as the primary switch to draw current from the battery to the starter motor. Because of its direct interaction with the battery and starter motor, it’s exposed to a significant amount of electricity.

Cause: When a starter solenoid becomes faulty or wears out, it might draw more electricity than it should normally do. As a safety measure, the fuse will blow to prevent overheating and potential damage to other electrical components.


  1. Regular Inspection: Regular upkeep and inspection of the solenoid can help prevent this situation. A multimeter can be used to test whether the solenoid is functioning correctly.
  2. Replacement of Solenoid: If the solenoid tests as faulty, it must be replaced to resolve this issue. Always remember to disconnect the mower’s battery before attempting to replace the solenoid.

Excessive Load on the Motor

The mower motor performs the heavy task of running the blades and, in some cases, propelling the mower. If the load on the motor becomes too great, the electrical draw can increase exponentially.

Cause: Situations like attempting to start the mower with a jammed blade, mowing on a slope, or trying to cut dense or wet grass can cause the motor to work harder than normal. This increased workload can cause an overload that the fuse can’t handle, leading to a blown fuse.


  1. Proper Mowing Practices: Ensure the mowing conditions are within the mower’s capabilities. For example, don’t try to mow very dense or wet grass and clean any built-up grass clippings from the blades.
  2. Routine Blade Maintenance: Regular inspection and maintenance of the mower’s blades can also help. Blades should be sharp and able to spin freely. Any obstruction to the blades should be cleared before starting the mower.

Addressing these issues promptly can effectively reduce the risk of blowing a fuse when starting your Honda lawn mower.

John Deere Lawn Mower Blows Fuse When Starting

John Deere Lawn Mower Blows Fuse When Starting
John Deere Lawn Mower Blows Fuse When Starting

Voltage Regulator Issues

The voltage regulator in your John Deere lawn mower modulates the voltage from the alternator to a consistent voltage that your mower’s battery and electrical systems can use.

Cause: If the voltage regulator isn’t working properly, it can cause an overcharge situation. This excessive voltage can potentially damage electrical components leading to a surge of current that the fuse cannot handle, resulting in a blown fuse.


  1. Engage a Professional: Voltage regulator issues can be complex and should be handled by someone sophisticated in electrical systems. Consulting with a professional mechanic can help diagnose and rectify voltage regulator issues.
  2. Possible Replacement: If the voltage regulator is found to be the issue, replacement of the component is typically the best course of action.

Faulty Safety Switches

John Deere mowers come with a variety of safety switches intended to prevent accidents and damage to the mower.

Cause: Sometimes, these safety switches can malfunction and cause a surge in current when the mower is started, causing a blown fuse as a protective measure.


  1. Regular Inspection and Maintenance: Ensure regular inspection and services to maintain the proper functioning of safety switches.
  2. Replacement of Faulty Switches: If a safety switch is determined to be the problem, replacing the faulty switch should resolve the issue.

Electric Lawn Mower Blows Fuse When Starting

Electric Lawn Mower Blows Fuse When Starting
Electric Lawn Mower Blows Fuse When Starting

Faulty Capacitor

Capacitors in an electric mower store energy from the power source and release it when needed.

Cause: If a capacitor is faulty or damaged, it might not store power adequately or might release excessive current suddenly, causing a blown fuse.


  1. Inspection and Replacement: Regular checking of capacitors for faults and timely replacement can prevent fuse from blowing.
  2. Consultation with Electrician: Electrical issues with capacitors can be tricky. Consulting with an electrician can provide a proper diagnosis and solution.

Damaged Power Cords

Power cords are a critical part of an electric lawn mower, supplying the mower with the electricity it needs to function.

Cause: Regular use, along with exposure to outdoor conditions, might wear down power cords over time, causing shorts that result in blown fuses.


  1. Routine Inspection: Regularly inspecting the power cords for any visible wear and tear can help to prevent a blown fuse.
  2. Replacement of Cord: If a cord has been damaged, replacing it before any fuse-blowing situation arises is the best solution.

Craftsman Lawn Mower Blows Fuse When Starting

Craftsman Lawn Mower Blows Fuse When Starting

Broken Ignition Switch

The ignition switch plays a critical role in starting the mower.

Cause: If the ignition switch is broken or faulty, the sudden fluctuation in current could blow the fuse when attempting to start the mower.


  1. Regular Inspection: Checking the ignition switch for any signs of wear and tear can help to identify potential issues before they cause a blown fuse.
  2. Replace the Ignition Switch: If it is found to be faulty, replacing it is the best choice.

Aged Battery

The mower’s battery supplies the initial power to start, run the engine and all other electrical components.

Cause: An old or failing battery might draw more current than the fuse can handle when trying to start the motor, potentially blowing a fuse.


  1. Routine Battery Test and Replacement: Regular testing of the battery’s health and ensuring replacement once its efficiency reduces substantially can prevent the blowing of fuses.
  2. Proper Care and Maintenance: A well-maintained battery can last longer and perform better. Ensure battery care by cleaning terminals and maintaining a full charge during off-season storage.


Several factors can cause a lawn mower to blow a fuse when starting, ranging from electrical issues such as short circuits and faulty components (like the PTO clutch, solenoid, and ignition switch) to mechanical problems such as excessive load on the motor.

Addressing these issues promptly, whether through regular inspection, maintenance, replacement of faulty parts, or seeking professional help, can go a long way in preventing your lawn mower from blowing fuses.

Adhering to proper mowing practices and conducting routine maintenance can ensure the longevity and efficiency of your lawn mower.

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