That frustrating “click, click, click” when you turn the key or pull the cord on your lawnmower is a common headache for homeowners. It signifies a problem preventing your mower’s engine from turning over, and while it can be infuriating, understanding the potential causes can help you diagnose and fix the issue. This guide will walk you through the common reasons your mower is clicking but not starting, providing you with practical troubleshooting steps and solutions to get your lawnmower roaring back to life.
Understanding the “Click”: What Does It Mean?
The clicking sound you hear typically originates from the starter solenoid. The solenoid is an electromagnetic switch that receives a signal from the ignition switch (or pull cord mechanism) and sends a large jolt of electricity to the starter motor. The starter motor, in turn, engages with the engine’s flywheel and spins it to initiate combustion. When you hear clicking, it usually indicates that the solenoid is trying to do its job, but something is preventing it from fully engaging the starter motor.
Low Battery Voltage: The Prime Suspect
The most frequent culprit behind the clicking issue is a low or dead battery. The solenoid requires a certain amount of voltage to operate correctly. If the battery voltage is insufficient, the solenoid may click repeatedly as it struggles to pull in and make contact.
Diagnosing a Low Battery
The first step is to check the battery terminals for corrosion. Corrosion can impede the flow of electricity. Clean them thoroughly with a wire brush and a mixture of baking soda and water. Rinse and dry the terminals before reconnecting them securely.
Next, use a voltmeter to measure the battery voltage. A fully charged 12-volt lawnmower battery should read around 12.6 volts or higher. If the voltage is significantly lower (e.g., below 12 volts), the battery is likely discharged.
Charging or Replacing the Battery
Try charging the battery using a battery charger specifically designed for lawnmower batteries. Follow the charger’s instructions carefully. If the battery charges but quickly loses its charge or still fails to start the mower, it may be time to replace it. Batteries typically have a lifespan of 3-5 years, depending on usage and maintenance.
Starter Motor Issues: When the Motor Itself Fails
If the battery is fully charged and the terminals are clean, the problem might lie with the starter motor itself. Starter motors can fail due to wear and tear, internal damage, or electrical issues.
Testing the Starter Motor
One way to test the starter motor is to bypass the solenoid. This is a potentially dangerous procedure and should only be attempted by someone comfortable working with electrical components. Use a screwdriver or a jumper cable to briefly connect the two large terminals on the solenoid. This directly sends power to the starter motor. If the starter motor cranks the engine, the problem is likely with the solenoid.
If the starter motor still doesn’t crank the engine after bypassing the solenoid, the starter motor itself is likely faulty and needs replacement.
Solenoid Problems: More Than Just Clicking
Even if the battery is good, the solenoid might be the issue. Solenoids can fail internally, preventing them from properly transferring power to the starter motor.
Diagnosing a Faulty Solenoid
As mentioned earlier, bypassing the solenoid is a primary diagnostic step. If bypassing the solenoid allows the starter motor to engage, it points directly to a solenoid problem.
Additionally, you can use a multimeter to check for continuity across the solenoid terminals when the ignition switch is engaged. If there is no continuity, the solenoid is likely bad.
Replacing the Solenoid
Replacing the solenoid is a relatively straightforward repair. Disconnect the battery before proceeding. Note the wiring configuration before removing the old solenoid and then install the new solenoid, connecting the wires in the same configuration.
Engine Problems: Impediments to Turning Over
Sometimes, the “clicking” sound can be a symptom of a larger engine problem that’s preventing the engine from turning over, placing a strain on the starter motor and causing the solenoid to struggle.
Low Oil Level: A Common Culprit
Many lawnmowers have a low oil sensor that prevents the engine from starting if the oil level is too low. This is a safety feature designed to protect the engine from damage.
Checking and Adding Oil
Check the oil level using the dipstick. Ensure the level is within the recommended range. Add the appropriate type of oil if needed.
Hydrostatic Lock: A Serious Issue
A hydrostatic lock occurs when liquid (usually oil or fuel) enters the cylinder and prevents the piston from reaching the top of its stroke. This can happen if the mower is stored improperly or if the carburetor leaks.
Attempting to Relieve a Hydrostatic Lock
Remove the spark plug. Carefully try to turn the engine over, either with the starter or by hand (if possible). Liquid should spray out of the spark plug hole. Reinstall the spark plug and try starting the mower.
Debris in the Cylinder: A Less Common Problem
Debris, such as small pieces of grass or dirt, can sometimes enter the cylinder and prevent the piston from moving freely. This is less common but possible.
Cleaning Debris from the Cylinder
Removing the spark plug and inspecting the cylinder with a flashlight might reveal debris. You can try using compressed air to blow out any loose particles. If the debris is significant, you may need to disassemble the engine for a thorough cleaning.
Safety Switch Issues: Preventing Accidental Starts
Lawnmowers are equipped with safety switches to prevent accidental starts. These switches are typically located on the seat, handle, or blade engagement lever. If one of these switches is faulty, it can prevent the mower from starting, even if the battery and starter motor are functioning correctly.
Identifying and Testing Safety Switches
Inspect each safety switch for damage or loose connections. Use a multimeter to test for continuity when the switch is engaged. If there is no continuity, the switch is faulty and needs replacement.
Common Safety Switch Locations
- Seat switch: Located under the seat.
- Handle switch: Located on the handle.
- Blade engagement switch: Located near the blade engagement lever.
Wiring Problems: A Hidden Cause
Faulty wiring can also cause a clicking sound. Corroded, loose, or damaged wires can interrupt the flow of electricity to the starter solenoid or other critical components.
Inspecting the Wiring
Carefully inspect all wiring connections for corrosion, looseness, or damage. Clean corroded connections with a wire brush and ensure all connections are secure. Replace any damaged wires.
Using a Multimeter to Check for Continuity
Use a multimeter to check for continuity in the wiring circuits. This can help you identify broken or damaged wires.
Maintenance Matters: Preventing Future Clicking
Regular maintenance is key to preventing the clicking problem and other lawnmower issues.
Battery Maintenance
Keep the battery terminals clean and free of corrosion. Store the battery in a cool, dry place during the off-season. Consider using a battery maintainer to keep the battery charged during storage.
Engine Maintenance
Change the oil regularly according to the manufacturer’s recommendations. Keep the engine clean and free of debris. Store the mower in a dry place.
Professional Assistance
If you’ve tried these troubleshooting steps and your mower is still clicking and not starting, it may be time to consult a qualified lawnmower mechanic. They have the expertise and tools to diagnose and repair more complex issues.
Why is my lawnmower just clicking when I try to start it?
The clicking sound you hear is likely the sound of the starter solenoid engaging, but not receiving enough power to fully turn the starter motor. This often indicates a problem within the electrical system preventing sufficient amperage from reaching the starter. Several common culprits include a weak battery, corroded battery terminals or connections, a faulty solenoid, or even a damaged starter motor itself.
To troubleshoot, begin by checking the battery voltage with a multimeter. A fully charged 12-volt battery should read around 12.6 volts or higher. Clean the battery terminals and cable connections thoroughly with a wire brush to remove any corrosion that might be impeding the flow of electricity. If the battery seems fine and the connections are clean, the problem might lie with the solenoid or the starter motor, requiring further testing or professional diagnosis.
How can I tell if my lawnmower battery is the problem?
A weak or dead battery is one of the most frequent causes of a clicking lawnmower. If the battery doesn’t have enough charge, it can’t provide the necessary power to turn the starter motor. This results in the solenoid clicking as it attempts to engage but fails to deliver adequate current.
You can test your battery using a multimeter. Set the multimeter to read DC voltage and connect the probes to the battery terminals (red to positive, black to negative). A reading below 12 volts indicates a low charge. Additionally, observe the battery terminals and cables for signs of corrosion, which can significantly impede electrical flow, even if the battery itself has a decent charge. If you suspect the battery, try charging it fully with a battery charger. If it still clicks after a full charge, the battery might be failing and need replacement.
What should I do if my lawnmower battery terminals are corroded?
Corrosion on battery terminals is a common issue that can prevent your lawnmower from starting. The corrosion acts as an insulator, blocking the flow of electricity between the battery and the starter motor. This blockage can prevent the starter from engaging, leading to a clicking sound.
To clean corroded terminals, disconnect the battery cables, starting with the negative terminal. Prepare a solution of baking soda and water. Using a wire brush, scrub the terminals and cable connectors thoroughly with the solution. Rinse with clean water and dry completely. Before reconnecting the cables, apply a thin coat of dielectric grease to the terminals to help prevent future corrosion.
Could a faulty starter solenoid cause the clicking sound?
Yes, a faulty starter solenoid is a very common cause of a clicking sound without the engine turning over. The solenoid acts as a switch, using a small electrical current from the ignition switch to activate a larger current from the battery to the starter motor. If the solenoid’s internal contacts are corroded, worn, or damaged, it might click but fail to complete the circuit needed to power the starter motor.
To diagnose a faulty solenoid, you can try bypassing it. Carefully use a screwdriver to connect the two large terminals on the solenoid (be aware that this can create sparks). If the starter motor engages and the engine starts, the solenoid is likely the culprit. However, if bypassing the solenoid doesn’t start the engine, the starter motor itself or the wiring to it may be the issue. Replacing the solenoid is often a relatively simple and inexpensive repair.
Is there a chance the starter motor itself is bad, even with the clicking?
Absolutely, even though you hear a clicking sound, the starter motor could be the problem. The clicking sound often indicates the solenoid is attempting to engage the starter motor, but if the motor’s internal components are worn, damaged, or seized, it won’t be able to turn the engine over. Common issues within the starter motor include worn brushes, a shorted armature, or a seized pinion gear.
To check the starter motor, you can try tapping it gently with a hammer while someone attempts to start the mower. Sometimes this can temporarily free a stuck component. If this works intermittently, it confirms a problem within the starter motor. Another test involves directly connecting the starter motor to a known good 12V power source. If it doesn’t spin, the starter motor is likely faulty and needs replacement.
What if the wiring to the starter is damaged or disconnected?
Damaged or disconnected wiring is a critical issue that can prevent your lawnmower from starting, even if you hear a clicking sound. The wires connecting the battery, solenoid, and starter motor are essential for delivering the electrical power needed to turn the engine. If these wires are corroded, frayed, loose, or completely disconnected, the circuit will be incomplete, preventing the starter motor from engaging.
Thoroughly inspect all wiring connections related to the starting system. Look for any signs of damage, such as frayed insulation, corrosion, or loose connections. Use a wire brush to clean any corroded terminals or connections. Ensure that all connections are tight and secure. If you find damaged wiring, repair or replace it with the correct gauge wire to ensure proper electrical flow.
Could a safety switch be the reason my mower is clicking?
Yes, safety switches are designed to prevent the engine from starting under unsafe conditions and can often be the reason for a clicking sound. Lawnmowers typically have multiple safety switches, such as those located on the seat, bail handle, or blade engagement lever. If any of these switches are faulty or not properly engaged, they can interrupt the electrical circuit, preventing the starter from turning over.
Check the operation of each safety switch individually. Ensure the seat switch is properly depressed (if applicable). Verify that the bail handle is fully engaged and that the blade engagement lever is in the correct position. Sometimes these switches can become dirty or corroded, preventing them from functioning correctly. Clean the contacts on the switches with electrical contact cleaner and ensure they are making proper contact. If a switch is faulty, it will need to be replaced.