Your mower won’t start and only makes a clicking or humming sound. Let’s troubleshoot the items that can cause this to happen so you can get your lawn-mowing task done.
A Toro lawn mower clicks and won’t start or turn over when the wires and cables are loose or corroded; the battery is weak; the ground is bad; the starter solenoid is bad, or the starter motor has failed.
Wear protective safety gear for protection. Consult a professional mechanic if you feel uncomfortable working with the electrical system.
Reminder: Always disconnect the negative cable (black) from the battery before making any repairs to the electrical system.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
More articles that may help with your starting problems:
- Mower won’t crank or turn over
- Mower won’t start
- Toro mower problems and solutions: troubleshooting tables
- How to tell your starter solenoid is bad
This is Why Your Toro Mower Clicks But Won’t Start or Turn Over
Damaged or Loose Battery Cables, Wiring & Terminals
The first place to start is to look at the cables and wiring. Make sure the cables from the battery to the solenoid and from the solenoid to the starter motor are securely attached.
Look for corrosion on the terminals and components. If you find corrosion, you will need to remove the corrosion.
SOLUTION: Replace any cables or wiring that keep coming loose or are broken. Bad cables on your Toro mower can contribute to a bad battery and starting issues.
Disconnect the battery from the mower and remove any components that have corrosion so you can clean them.
A wire brush and a baking soda mix consisting of 2 cups of water and 3 heaping tablespoons of baking soda work well. Repair or replace any wiring that has signs of corrosion.
Add a dielectric grease to protect terminals and wiring from corrosion. Replace terminals when they are damaged or in bad condition.
Bad or Weak Battery
When your battery is no longer fully charged and has become weak, it may not provide enough power to turn over the engine to start it.
Check the battery voltage level. If it is low, place the battery on a battery charger to charge it. When you find the battery won’t hold a charge, it is bad and must be replaced.
If you find you are able to charge the battery but it just keeps dying, you may need to check the Toro’s charging system. Refer to the charging system section near the end of the article.
Check the voltage of the battery
Use a multimeter’s red and black prongs and touch them to the terminals of the same colors. Most batteries used on a mower are 12-volts.
On a 12-volt battery, you may get a voltage reading between 11.5 and 12.7. A battery that is almost dead will register closer to 11.5V while a battery that is fully charged will read 12.7V.
Charge a Toro lawn mower battery
- Put on your safety gear so your eyes and skin are protected from acid or electrical shock.
- Get access to the battery and its terminals. You may need the screwdriver to uncover the lawn mower’s body to get access to the battery or battery casing.
- Leave the battery in its casing with the terminal cables attached.
- Connect the charging cables starting with the red cable first (The one with the positive sign on it)
- The red cable clamp goes onto the positive terminal, and the black cable clamp goes on the negative battery terminal.
- Make sure that your skin only touches the rubber coating of the charging cables and clamps.
- Set the charger’s voltage level and amp level to the desired level. The average volt level for a lawn mower is usually 12 volts. More amperage charges the battery faster (Start with two amps and work up to no more than 10 amps).
- If your charger has a battery charging gauge, keep the charger connected until the battery is fully charged.
SOLUTION: When the battery is weak, use a battery charger to charge it. If you find the battery will no longer hold a charge, it’s time to replace it with a new battery.
If the battery is able to be sufficiently charged using a battery charger, but you continually find it dead when you go to use your mower, you should look for a problem with the charging system.
Check the black ground cable that runs from the battery to the frame on your mower. It must make good contact and be free of corrosion.
You also need to check the ground from the solenoid. A 3-post solenoid is self-grounded.
SOLUTION: Replace a damaged ground cable. Remove any corrosion found for the grounds from the battery and the starter solenoid.
Bad Starter Solenoid
When your mower keeps clicking, a likely cause is a bad lawn mower starter solenoid. The solenoid acts like an on-off switch. It is an electromagnet switch that is actuated to engage the starter motor so the engine will turn over.
Most starter solenoids are mounted on the starter. However, they do not have to be to still work. Follow the positive wire from the battery to find the solenoid.
There are many reasons why a starter solenoid can go bad. The internal spring can become weak or the copper plate can start to corrode.
A bad ground, weak starter, or bad battery can also result in the starter solenoid failing.
SOLUTION: Test your starter solenoid. You’ll need a volt-ohms meter, screwdriver, continuity light, and some wrenches.
Follow the instructions found in “How to Tell Your Lawn Mower Solenoid is Bad“. If you are able to start your mower by bypassing the solenoid, it must be replaced.
Bad Starter Motor
If you’ve checked the battery, cables, wiring, ground, and starter solenoid only to find them in good condition, but still have a starting problem, your starter may be the problem. The starter can be removed and tested.
SOLUTION: A starter can be a pricey item on a lawn mower. I advise having your local dealership confirm you have a starter motor problem before you replace it.
You can also bring the starter to a local repair shop that specializes in starter and alternator repairs. The personnel at the repair shop can test the starter and may be able to rebuild it.
Bad Toro Charging System Drains the Battery
A bad charging system on a zero turn, lawn tractor, or riding mower will not keep your battery charged and in turn cause a weak battery to not start your mower.
Perform the steps provided here to check the charging system using a volt-ohms meter.
If you find your lawn mower is no longer charging the battery, I recommend having a mechanic familiar with your charging system perform further tests and necessary repairs.
Troubleshooting the exact cause of a charging system can be quite difficult.
If you’re not familiar with the charging system, you will probably just end up throwing parts at your mower.
This can get very expensive, especially since if you get it wrong, you can’t return an electrical part. You could be looking at a bad stator/alternator, regulator, or other electrical problem.
Still Having Problems with Your Toro Lawn Mower?
It would be great to own a problem-free lawn mower, but it’s never the case. No matter what brand mower you own, you’re going to run into problems the longer you own it.
To help you troubleshoot your mower problems, I have put together a list of common problems along with causes and solutions to fix them. Check out Common Toro Lawn Mower Problems and Solutions to learn more.