It could be a variety of factors if your riding lawn mower does not start when you flip the key to start the engine. It can be anything from loose battery connections, fuses, the ignition switch, or something more serious.
Luckily, if you end up saying my riding mower does nothing when I turn the key, you can go through some troubleshooting on your riding lawn mower before you need the help of a dealer.
In our guide, you can find out more about a John Deere or Husqvarna riding lawn mower won’t start no clicking or any other model you have. By the end, when you face not even a click, you’ll have enough information to run through the starting procedure to check all the items that could cause the issue.
Then, in the space of minutes, you could pinpoint the problem and get mowing your lawn without further issues. (Read Riding Lawn Mower Snow Blower Combo Guide)
How Do I Know If My Riding Lawn Mower Solenoid Is Bad?
What does it mean when you flip the key and hear a click? When you hear the click, the starter solenoid coil receives power from the battery via the ignition switch.
If you don’t hear that click, the starter solenoid is broken, or the starter solenoid coil isn’t receiving power.
We’ll teach you how to find the problem by inspecting the battery, solenoid posts and coil, fuse, ignition switch, brake interlock switch, and blade switch on your riding mower.
While lawnmowers are different, much of the troubleshooting techniques are the same. The fundamental distinction is that you may need to consult your model’s wiring diagram if you detect issues.
How riding mower starting system operates:
It helps to know how the starting system works to narrow down the problem. Many issues look like problems when safety switches are engaged. Make sure no safety switch affects your troubleshooting.
- The positive red battery connection connects to one of the starter solenoid terminal posts (positive).
- The black wire that connects to the other major terminal on the starter solenoid (negative) provides power to the starter motor, which allows the engine to start.
- A short red wire runs from the red solenoid terminal post to the ignition coil at the bottom of the starter solenoid, carrying power through the ignition switch.
- The ignition switch provides power through the white wire to energize the coil within the solenoid when you turn the key to the start position.
- The coil closes an internal contact, sending power from the red battery connection to the black wire, which turns the starter motor.
Do I have a dead battery?
A dead battery will prevent the solenoid coil from clicking since it will not power up the starter system.
- Use a multimeter to measure the DC voltage across the battery terminals to inspect the battery.
- Put on your safety goggles and work gloves.
- Remove the key from the ignition.
- Look at the battery. To access the battery on this style of riding lawn mower, you must elevate the seat.
- Touch the red multimeter probe to the positive or red battery terminal and the black multimeter probe to the negative or black battery terminal with the multimeter set to measure DC voltage.
- The battery should measure over 12 volts of DC if it is in excellent condition.
- If it’s less than 12 volts, you have a weak or dead battery, and you’ve probably located the source of the problem. The starter solenoid coil will not power if the battery is weak or dead.
- Using a charger, try recharging the battery. In a pinch, you can use jumper cables to jump-start a riding lawn mower with a 12-volt battery.
- Replace with a new battery if it won’t charge.
If the battery is weak or dead, you can find there isn’t enough power for the fuel pump. The fuel filter could also cause issues with lack of fuel. Checking or changing the air filter can also help while doing your troubleshooting.
A valve lash issue is much different. Fixing a valve lash problem is more intensive than checking the battery and terminal connections. (Read Troy Bilt Riding Mower Oil Type)
Check solenoid power
If the battery works appropriately, power is delivered to the red battery cable. Is voltage flowing to the red terminal post through the red battery cable? To verify this, take a voltage reading at the red terminal post.
- Connect the multimeter’s red probe to the starter solenoid’s red post and the black probe to the battery’s negative terminal. It should measure more than 12 volts.
- Check the battery terminals and cable leads for corrosion if the battery voltage is less than 12 volts. Use a wire brush to remove rust from the battery terminals and battery cable leads; corrosion can prohibit the red solenoid post from receiving power.
- Recheck the voltage. Replace the red battery wire if it still doesn’t measure over 12 volts at the red post.
Check solenoid coil power
Now you’ve established the red terminal is receiving power, you need to determine if the solenoid coil is receiving power when you turn the key on your lawn tractor. Or, you have a faulty solenoid, leaving you with a tractor won t start, no click.
The starter solenoid is to blame if the voltage is measured at the coil, but the internal contact does not click. However, when the solenoid gives power to the starter motor, it clicks.
- Unless you have a helper to turn the ignition key while you hold the probes on the solenoid coil wires, you’ll need clip-on meter probes. Remove the white and black wires from the solenoid’s spades.
- Set the multi-meter to DC voltage measurement.
- Connect the white wire female spade connector to the red meter probe and the black wire female spade connector to the black wire female spade connector.
- Turn the ignition key to the start position, then note the voltage reading on the meter display before turning it off.
If the battery voltage is measured with a multi-meter, it will be greater than 12 volts. The starter solenoid should be replaced if the coil receives power but does not close the internal contact to the starter motor.
There is a break in the circuit to the solenoid coil if it reads 0 volts. The starter solenoid is most likely fine; it simply lacks power. It’s time to test the coil circuit. (Read Riding Lawn Mower Won’t Stay Running – What To Do)
Test lawnmower coil circuit
First, we’ll test the circuit’s ground. The black wire links the solenoid coil to the metal frame of the riding mower. A wire break prevents power to the coil.
- Using a meter, we check for resistance between the black wire’s female spade and the metal frame of the mower and ground wire.
- Before testing resistance, disconnect the negative battery cable and positive battery cable from the mower.
- Keep the cables away from the battery terminals, so they don’t accidentally restore power to the posts.
- Set the multi-meter to measure resistance and ground it by touching one probe to the black wire female spade and the other to the bare metal on the mower frame.
Resistance around 0 ohms suggests the black wire is grounded. Infinite resistance shows a break in the black ground wiring. The engine should start after the black wire has a good path to ground.
Next, you’ll need to check the hot side of the circuit, which starts with the small red wire on the starter solenoid terminal and finishes with the white wire that connects to the coil spade, if the ground side is alright.
A fuse, the ignition switch, the brake switch, and the blade switch are all part of the circuit.
- Start with the simplest and check for a blown fuse, which you can tell by glancing at it.
- The fuse on this mower is immediately next to the starter solenoid, but we have to remove the battery and battery box to get to it.
- Pull the fuse from the holder using the zip tie.
- If you’re not sure if the fuse is blown, use your multi-meter to check for continuity through the fuse.
- Remember, if the fuse blew because of a component or wiring fault. You’ll need to figure out what’s causing a blown fuse and how to fix it.
- Reinstall the fuse in the holder and secure it with the zip tie.
A blown fuse or broken connection will measure infinite resistance. Infinite resistance means you’ll need to replace the parts. (Read Poulan Pro Riding Lawn Mowers Reviews)
How Do I Know If My Lawn Mower Ignition Switch Is Bad?
On your lawn tractor, many areas can cause issues with starting. Here’s a quick rundown of what you would check first.
Check battery voltage, 12.65v is fully charged, 12.05v is half-charged, and needs recharging.
Low voltage shows a defective battery that may not recharge. A battery must be charged to be tested; hence a battery charger is required. The mower’s alternator will eventually charge the battery if it isn’t malfunctioning. You can try the crank test once the battery is fully charged (about 70%).
If the lights don’t function, use a voltmeter to test the battery’s charge, or you could have a blown fuse.
If you don’t have a charger, a set of jumper wires and a car or any 12volt battery will do.
Check Safety Sensors
Riding mowers are fitted with safety measures to prevent operator error or accident. Sensors/switches regulate safety features on mowers, which are usually wired into a control module. One of the more common is the weight sensor in the seat, so the starting procedure can’t finish unless you are sitting on your mower.
Check Control Module
Modern mowers contain control modules, printed circuit boards comprising relays and resistors.
Assuming that all sensors are engaged, the control module starts the starter when the ignition switch is turned on.
Visually inspect these modules for loose connections or water damage, as each module comes with an internal or external fuse. For example, a mower’s primary fuse might blow, cutting off power to the ignition system.
Check Ignition Switch
Improperly connected ignition switches can cause a host of issues with the ignition system. Ignition switches can convey commands to the control module.
If your mower lacks a control module, the safety sensors are directly connected to the ignition switch, leaving it open.
- Problems with ignition switches include loose wiring, rusted or damaged terminals, and spinning ignition switches.
- If you have the blade knob set to the on position, your engine won’t start. So make sure your ride-on mower is in the park and the knob set to off.
- Remember, you’ll need someone to sit on the mower seat as you check the connectivity of the ignition wires and connectors.
When I Turn The Key On My Mower Nothing Happens?
Test Ignition Switch
Check continuity through the red wire from the starter solenoid post to the ignition switch.
- Assemble a test set up for the red starter solenoid wire and the ignition switch
- Open the mower hood.
- Remove the ignition switch wire harness.
- Pull the ignition switch out of the dash by the locking tabs.
- Push the wire harness plug through the hole to test the contacts.
- Place one probe on the starter solenoid post with the red wire and the other on the female plug spade with the red wire.
- This section of wiring should have near 0 ohms’ resistance. Find and repair the red wire’s break if you get infinite resistance.
Test Brake Interlock Switch
We’ve isolated the circuit break to the part of the white wire that includes the brake switch and blade switch if the ignition switch is working. (Learn How To Cut Grass With Riding Mower)
- Remove the air duct mounting screws and pull out the brake switch.
- Remove the fuel tank with care. If the tank is weighty, drain some fuel.
- Remove the lower dash fastener and take it off. Now you may try the brake switch.
- Note the white wires’ prongs, as these are the ones you’ll need to test the brake switch’s resistance.
- Pull the wire harness off the brake switch.
- Touch one probe to one prong and the other to the other prong that connects to the white wires.
- If the brake switch works properly, it should measure near 0 ohms.
- If you have infinite resistance, the brake pedal switch is broken.
You must disassemble the clutch lever assembly to reach the blade switch.
- Note the white wires’ prongs and remove the wire harness from the blade switch.
- Set your multi-meter to examine resistance and touch the probes to the white wire’s prongs.
- The multi-meter should read near 0 ohms if the blade switch is working. If it reads infinite resistance, replace the blade switch.
- If the blade switch works, a break in the white wire between the ignition switch and the solenoid coil prevents the coil from receiving power. Locate and fix the wiring fault.
After reading our troubleshooting tips, you should be able to start your mower.
How Do You Test A Starter Solenoid On A Riding Lawn Mower?
Riding lawn mowers come with many safety features and safety switches to stop the engine from starting unless certain conditions are met.
- Parking Brake: Ensure the parking brake is engaged. This safety switch can be part of the brake pedal.
- Blade Control: The blade control handle must be in the OFF position.
- Seat cutout: Most riding mowers have a seat safety switch.
Wiring and Connections
Like any other internal combustion engine, the starter motor requires a solid battery connection.
- Inspect the starter, solenoid, ignition switch, and battery connections. Remove corrosion with a wire brush and tighten all connections.
- Check the grounding points.
Grease or use liquid electrical tape for all connections.
- Verify the starter motor bolts. Otherwise, the starter may move and not engage.
Bad Starter Solenoid
If you have a decent battery, but the riding mower won’t start when you turn the key on your riding mower, your solenoid may be broken and won’t pass any current through the ignition wiring to the spark plug.
The solenoid is simple to check with a 12V battery and a multi-meter
- Unscrew the solenoid from the riding mower
- Most solenoids have four posts: two for operation and two for battery connection.
- Connect your multi-meter to the two large battery posts to test continuity.
- Connect the battery’s negative to a spade terminal.
- Connect the battery’s positive terminal to the other spade terminal:
- The solenoid should click as it works.
- Continuity/short circuit should show on your multi-meter.