Dealing with a non-starting riding mower can be incredibly frustrating. However, if you’re experiencing a situation where the engine doesn’t make any clicking sounds, there may still be hope for a simple fix without having to replace the mower just yet.
I’ve come across numerous instances where a riding mower won’t start or even click. Let me share with you some potential issues and troubleshooting tips to get your riding mower back in action.
How to Fix a Riding Lawn Mower That Won't Start
“Should I call a professional when the riding mower does nothing when I turn the key?” The answer is: not always. You should be able to find out the problem with your tractor or mower yourself. But first, ensure you set the parking brakes.
Then check if the blade is still disengaged. Your riding mower won’t work otherwise.
Materials You Will Need
- Work gloves
- Safety goggles
- Multi-meter
- Screwdriver
- Wire brush
How a Riding Lawn Mower is Powered
From my extensive experience with riding mowers, I can tell you that they typically operate on a four-cycle engine, cycling through intake, compression, combustion, and exhaust phases. While many mowers I’ve worked with use gasoline and rely on a spark plug for combustion, there are also those that run on diesel, eliminating the need for a spark plug. Regardless of the fuel type, once that engine gets going, it powers the transmission, drives the wheels, and spins those cutting blades underneath.
Like automobile car, riding mower requires to charge a battery, starter motor, and ignition switch. When you turn the ignition switch to the ‘Start’ position, 12 volt of direct current travels from the battery through the starter solenoid to the starter motor. This current also flows through a cable to the anti-afterfire solenoid in the engine
When you release the key to the ‘Run’ position, this DC of twelve (12) volts is then redirected. Instead of going to the starter and motor, it moves to the alternator and anti-afterfire solenoid only. Together, these parts help to charge the battery and start auxiliary power sources like headlights and power plugs.
If your high-quality zero turn mowers work fine, you would hear a clicking sound between the ‘Run’ and ‘Start’ positions. This implies that the starter solenoid is getting power from the battery. On the other hand, when you don’t hear a click from the engine, the starter has failed, or its coil isn’t getting power from the battery.
Although mowers differ from models, they all work on the same principles.
Check and Charge/Replace Dead Battery
Battery troubles are one of the most common reasons a mower won’t run or click. A corroded battery won’t start an engine, and neither will a drained battery, when you forget to turn off the safety switch. Corrosion can be a usual problem for used riding lawn mower models at cheap prices of $500 below, so make sure to check this when you buy one.
I’ve often found that a service monitor can be invaluable in pinpointing battery issues. However, if you don’t have one, don’t fret. I’ve checked batteries countless times using a multi-meter. Just follow these steps:
- Turn off the ignition system before accessing the battery.
- Set the multimeter to DC voltage
- Use the multi-meter's red probe to touch the positive terminal and the black probe on the negative terminal.
If the multitester reads more than twelve (12) volts, the battery is good. Otherwise, it is weak, or dead and you’ve found the problem with your mower.
- Accessing the battery, which is usually under the driver's seat.
- Connecting the charger clips to the battery terminals.
- Plugging the charger to a power outlet. The charger should work on at least 10volts to charge the battery. Still, a 12-volt charger is sometimes preferred.
- Disconnecting the charger reversing the steps above.
- Plugging the charger to a power outlet. The charger should work on at least 10volts to charge the battery. Still, a 12-volt charger is sometimes preferred.
- Replacing the seat and reconnecting the new battery in your mower correctly.
If a simple recharge doesn’t work, you need to replace the battery pack in the mower. Avoid a jump start mower to prevent damages to the on-board system
Check the Ignition Switch
The problem with your mower could be with the switches. When you start the engine and your riding mower does not forward nor reverse, your ignition switch’s contacts complete a circuit. This circuit is from a red to a white wire, which is on the B-terminal and S-terminal, respectively.
I suggest checking the switch by measuring the resistance between these terminals.
- Pull up the mower's hood to access the ignition switch.
- Remove its cable harness.
- Remove the tabs to pull the ignition switch out of its slot.
- Turn the key to the start position and set the multi-meter to measure resistance, not voltage.
- Connect the black multi-meter probe to the B prong and the other to the S prong. These terminals are along each other's diagonal at the bottom of the switch.
- Use the key to turn the ignition switch and start the engine. The resistance should display on the multi-meter when you do this.
The top-rated riding mowers should have good ignition switch measuring 0 ohms. This means its contacts complete the B and S terminal circuit and can send voltage to the solenoid. On the other hand, a damaged ignition switch will measure infinite resistance.
Other common issues you can experience with a damaged ignition switch include loose wiring and connections, corrosion, or spinning ignition. To fix this problem, check the ignition wiring for corroded, damaged, or loose wires
Inspect the Control Module
A control module is a printed circuit with resistors, relays, and a ground side that receive commands from the safety switches. If the sensors in the motor work correctly, a circuit module will also output a command to the starter through the solenoid. But keep in mind, not every mower I’ve come across is equipped with one.
Depending on your model, a control module could be anywhere, even under the seat. And if you notice that your high-quality electric riding mower won’t start and no clicking comes from the device, or cranking doesn’t work, then this module could be faulty.
There are two ways to check the control module yourself:
- Wiggle test: Here, wiggle the red and black wires connected to the control module while you start the mower. If everything checks out fine and the wires are connected, visually check the printed circuit for water damage and loose connections. To save time, you may have someone help you with the wires in a wiggle test while you focus on finding the issue.
- Main fuse check: Modules have internal or external fuses, and a blown fuse cuts out the supply from the battery. First, to check the fuse, remove its zip tie and then pull the fuse from its holder. If any element in the fuse is broken or there's a fault in the ground connection, you should have it replaced. However, if you're unsure, you can check for continuity using your multi-meter.
Check Safety Functions
Every mower even the cheapest riding mower you can find in the market has in-built safety features. Typically, sensors or switches control these features, and they are routed through the control module. Once a detector activates a safety function, your mower won’t work as usual.
The main ones to check are the brake pedal switch, blade switch, battery connection, weight sensor (to make sure a driver is sitting before the mower works).
When you jump start the engine, you should press your brake pedal. If the brake pedal doesn’t work, then you need to inspect your brake detector.
- Remove the hood and air-duct screws.
- Pull off the air duct and take the fuel tank and filter out of the way.
- Pull the cable harness off the brake switch, noting the wiring.
- Using the multi-meter probes, touch both prongs that connect to the wiring of the brake detector.
If the brake switch is okay, the multi-meter should display 0 ohms of resistance. Replace this switch if you read infinite resistance from your multi-meter.
A riding mowers engages when the blade knob is switched off or the transmission isn’t set to park. To check the blade switch, I recommend to do the following:
- Take out the clutch lever mounting screws. The assembly should drop slightly when the screws aren't in place.
- Note the prong's wiring and then disconnect the blade switch's cable harness.
- Using your multi-meter probes, touch both prongs to measure the resistance of the blade switch.
Like before, 0 ohms implies your blade switch is good, while infinite resistance means you need to replace it.
Motion detectors, switches, and sensors have in-built override functions. These functions are generally used for tests, and simply disconnecting a detector can cause an override. If you suspect your sensors are on an override, I suggest reconnecting them before starting the device.
Replace Faulty Solenoid
Follow these steps to change a faulty solenoid:
- First, raise the seat to get to the battery. Then, disconnect the battery terminals, starting with the negative (colored black) and then the red
- Remove the battery from its slot. While at it, check for leaks or corrosion at the bottom and sides. Clean corrosion off the cable leads with a wire brush if they are still there after dusting.
- Disconnect the cable harness that's connected to the seat's detector.
- Pull off the battery box after removing its clips or screws.
- Note the wiring connected to the solenoid and then disconnect the cables in any order.
- Remove the mounting and tab both with a screwdriver.
- Remove the faulty solenoid and replace it with the new one.
- Finally, replace the seat, battery, and other parts.
While you can repair some solenoids, it’s often better to change them for longevity. In this way, you can still have the opportunity to place your riding lawn mower on retail in the long run given that the equipment is properly maintained.
FAQ
Why does my riding lawn tractor click but won't start?
Your riding lawn tractor click but won’t start because the trouble could be from your battery, fuse, control module, or mower’s safety features. You’ll often just need to recharge your battery or change the fuse to power your lawn tractor again for mowing season.
How do I know if my mower solenoid is bad?
You will know if your mower solenoid is when you listen to what happens when you turning the key while starting the mower. You should hear one click when the solenoid engages. If it doesn’t make this sound, your bad starter solenoids have an issue and need a repair or replacement.
What do you do when your riding mower won't start?
When your riding mower won’t start, carefully go through the starting procedure. Sometimes, you might have forgotten a step like pressing the parking brake or standing while starting the device. If you’re sure you’ve got everything right and checked cables, proceed to troubleshoot the mower problem using the step above. You’ll save time if you start from a battery and fuse test.
Conclusion
Having dealt with countless mowers, I understand the frustration when your riding mower doesn’t start, there’s no clicking sound, and cranking proves fruitless. But, no matter the model you’re working with, I’ve developed some tried-and-true troubleshooting methods. Trust me, if you follow these tips closely, you’ll have a good shot at getting your mower up and running.
Is mowing your uneven and hilly lawn a challenging and daunting task? Then, getting these topnotch riding mower for hills might be an ideal solution. Read next!
You've probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.
Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.
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