It’s frustrating when you finally find time in your busy schedule to get your lawn mowed only to find out your zero-turn won’t turn over. I offer some tips to check when you run into this issue so you can your mower up and running again.
A zero-turn mower won’t turn over because of a bad battery; loose or corroded wires; corroded terminals; a blown fuse; a bad ignition key switch; a bad safety switch; a faulty starter solenoid; or a bad starter motor.
Take caution when working with your zero-turn’s starting system. Wear safety gear and follow all safety precautions outlined in the operator’s manual for your zero-turn model.
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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.
This is Why Your Zero Turn Mower Won’t Turn Over
Dead or Bad Battery
A zero turn with a dead battery will not turn over. Charge your battery and check it to see if it is able to hold a charge. If it fails to hold a charge, you must replace your battery with a new one.
A new lawn mower battery can be purchased at your lawn mower servicing dealership or at your local hardware or automotive store. Make sure you bring your old battery with you when you purchase a new one.
Most of the time, you will be charged a core charge if you don’t provide them with your old battery.
Charging a lawn mower battery:
Use a battery charger to charge your 12-volt battery. Before you continue, wear protective gear to protect your eyes and skin from electrical shock. Follow these steps to charge your lawn mower battery with a charger:
- Access the battery and terminals. You may need to use a screwdriver to uncover the battery. Do not remove the battery from the casing.
- Connect the charging cables beginning with the positive cable first. This is the red cable or the one with the plus sign. Place the cable on the positive battery terminal.
- Attach the negative cable to the negative battery terminal. This is the black cable or the one with the minus sign.
- Do not touch anything that doesn’t have a rubber coating to prevent electrocution.
- Set the charger’s voltage and amperage level to the desired level. The average volt level for lawn mower batteries is usually 12 volts. More amperage charges the battery faster. Start with two amps and work up to no more than 10 amps. A slow charge is best.
Loose Wires and Connections
Check the electrical wires and connections on your zero-turn. When you operate your zero-turn, there is a constant vibration that can cause your connections to become loose. Water can also collect in your connections and make them corrode and not function properly.
Clean any corrosion you find on the connections using a wire brush and a baking soda solution. You can make this solution using 2 cups of water to 3 heaping tablespoons of baking soda. If your connections and terminals are severely corroded, replace them.
Replace or fix any wires between the starting components that have breaks in continuity or are damaged.
Bad Fuse
A fuse is installed to protect your zero-turn’s electrical system. Check your mower to make sure you don’t have a blown fuse. If you’re unsure if the fuse is blown, you can check it by placing a multimeter probe on each prong of the fuse to measure resistance.
A resistance reading near 0 means your fuse is good. An infinity resistance reading indicates a bad fuse.
Replace a blown fuse with a fuse of the same amperage as the fuse you are replacing. If you continue to blow fuses, you should bring your zero-turn to your lawn mower dealership or lawn mower repair shop to troubleshoot the root cause.
Bad Ignition Switch
The ignition key switch can be the culprit if you insert the key and turn it to find nothing happens. Your zero turn will fail to start.
Check the switch using a multimeter to check continuity to determine if the ignition switch is the problem. To do this, look for the prongs mark B for Battery and S for Starter Solenoid.
Insert the key and turn it to the start position. With the multimeter set to measure resistance, touch one probe to the B prong and the other probe to the S prong.
A good ignition key switch will measure resistance near 0 ohms. A bad ignition key switch will measure infinite resistance and will need to be replaced.
Bad Safety Switch
Your zero turn has an operator presence control system installed to keep you safe. A safety switch can be defective and cause your zero-turn to fail to turn over.
Test your switch using a multimeter. You can also temporarily bypass the safety switch to identify a bad switch, but only do this for troubleshooting purposes.
Never operate a mower without the safety switch. Never run a mower when a safety switch is bypassed. A safety switch can save you from serious injury and you never know when you’re going to need it.
Bad Starter Solenoid
A starter solenoid is an electromagnetic switch that, when engaged, initiates the starter motor to turn over your zero-turn engine.
The starter solenoid can go bad when the spring becomes weak or the copper plate begins to corrode causing your zero-turn to no longer turn over. A weak starter, bad battery, or bad ground can also cause the solenoid to fail.
Before you test your starter solenoid, you must have a fully charged battery. Continue testing the solenoid by using the steps to diagnose a bad starter solenoid in “How to Tell Your Lawn Mower Solenoid is Bad”.
Bad Starter Motor
Once you have ruled out the battery, cables, wiring, ground, and starter solenoid as being the reason your zero-turn won’t turn over, it’s time to look at the starter. The starter can be removed and tested.
I recommend having your local repair shop that specializes in starter and alternator repairs test your starter and rebuild it if possible before just throwing a pricey new starter at your zero-turn.
Still Having Problems with Your Zero Turn Mower?
If you have checked the above items and none of them resolved the issue with your zero-turn mower turning over, you may want to check out the articles below or take your mower to your local lawn mower repair shop for further diagnosis.
You can also check out my guide for more problems and solutions: Common Zero Turn Problems: How to Fix Them