When your mower won’t start and the engine won’t turn over, you need to identify and check items that will keep the starter motor from getting power so it can spin the engine.
A Troy-Bilt lawn mower won’t turn over or crank due to a bad battery, loose or corroded wiring and electrical components, faulty ignition switch, bad safety switch, blown fuse, bad starter solenoid, or a bad starter motor.
Take safety precautions to prevent injury. If you are uncomfortable or don’t have the skill level to work with the electrical system, consult a knowledgeable mechanic.
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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.
Why Your Troy-Bilt Mower Won’t Turn Over
Dead or Bad Battery
A weak battery won’t provide power to turn over a Troy-Bilt mower. It’s important to keep it fully charged, especially when you are storing the mower for extended periods, to make the battery last longer.
Test your battery using the steps in the article 5 Things That Are Draining the Life of Your Lawn Mower Battery.
Charging a 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 negative 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.
If the battery fails to hold a charge it must be replaced with a new battery. You can purchase a new battery at your location lawn mower dealership, hardware store, or automotive store.
Bring your old battery with you. Most places will charge you a core fee unless you provide them with your old battery.
Loose or Wires and Connections
After checking the battery, check the cables and connections. The mower’s vibration and bouncing around when mowing can cause cables, wiring, and connections to become loose.
Make sure the connections are secure and there is no corrosion buildup that can cause a break in continuity. Moisture on connections can cause connections and terminals to begin to corrode.
Try to remove this corrosion using a small wire brush and a baking soda solution (2 cups water to 3 heaping tablespoons of baking soda). Disconnect the battery and remove the components before cleaning them.
Replace the terminals or components if the corrosion is severe and you are unable to sufficiently clean them.
Bad Fuse on Your Troy-Bilt Lawn Mower
A fuse is installed to protect your mower’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 the same amperage as the fuse you are replacing. If you continue to blow fuses, you should bring your mower to your local Troy-Bilt 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 mo will fail to turn over and 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 Troy-Bilt has an operator presence control system installed to keep you safe. A safety switch can be defective and cause your mower 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 Troy-Bilt’s engine.
The starter solenoid can go bad when the spring becomes weak or the copper plate begins to corrode. A weak starter, bad battery, or bad ground can also cause it 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 it 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 mower 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 mower.
Still Experiencing Troy-Bilt Lawn Mower Problems?
Own a lawn mower long enough, you’ll start running into problems with it starting, not continuing to run, smoking, leaking gas, giving a bad cut, vibrating, or another issue.
To help you save time and money, I have put together a guide to help you troubleshoot the next problem that develops on your Troy-Bilt mower.
You can find this guide at Common Troy-Bilt Lawn Mower Problems & Solutions.
If you are unsure how to perform diagnostics and repairs on your lawn mower safely, it’s best to have a professional complete the repairs.
This will help you avoid personal injury or additional damage to the mower. Your local Troy-Bilt lawn mower dealership or lawn mower repair shop will be able to help you solve your problem.