When you turn your key on your riding lawn mower, you’ll hear the all-familiar click. This is the sound that your riding mower is ready to start and that a relay has activated. Unfortunately, you don’t always hear the click. To figure out what’s going on, you’re going to have to dig into the starter electrical circuit and diagnose what’s causing the problem. Let me walk you through the process.
Riding Lawn Mower Won’t Start with No Clicking (The Short Explanation)
The click the lawn mower makes when the key is turned to the ON setting is made by the starter relay. The starter relay is connected to an electrical circuit made up of several parts, which can each individually malfunction and prevent the starter relay from activating and clicking.
Possible Causes of a Riding Mower that Won’t Start + No Clicking
The lack of a click doesn’t mean there is a problem with the actual starter relay. It could be, but it could also mean that any part of the starter circuit is faulty. Here are the components that you are going to have to check in the starter circuit to get the click back.
- Battery
- Ignition
- Fuse
- Cabling
- Connections and Terminals
- Starter Relay
Let’s take a look at the components that make up the starter circuit and see what they do to help you diagnose why your riding mower does nothing when you turn the key.
A Problem with the Battery
The battery is the component that provides power to the entire starter circuit. A dead battery could be the reason you’re not hearing a click sound. The starter relay needs a specific amount of power for it to activate and protect the ignition circuit.
Testing the Battery
The easiest way to check the battery is to use either a battery tester or a multimeter. If your lawn mower has a 6v battery, then when it is fully charged, it should be tested at close to 7v. If your mower has a 12v battery, then this battery should be tested at close to 12.6v.
A Faulty Ignition
Next on the list is a faulty ignition. This isn’t a common issue, but it could have taken a knock or have had some kind of short which renders it faulty. Also, don’t be fooled; just because it’s still powering things like your lights, it could still be the cause of the problem.
Testing the Ignition
Again, you will need to grab your multimeter or voltmeter and check the power passing through the ignition when it’s switched to ON. You will need to check the ignition to make sure that you have a good reading (matching your battery voltage) when it’s switched to ON and nothing when it is switched to OFF.
Circuit Fuse
Each of the electrical circuits on your riding mower are going to have its own fuse, and this includes the starter circuit. If you are not sure where yours are, then it would be a good time to dust off the old manual. Failing this, try looking under the mower’s hood or under the seat.
Check the Fuses
Once you have located your starter fuse, you are going to want to remove it for inspection. A blown fuse is pretty easy to spot once you have it removed from its holder. Check to see that the fuse wire inside the fuse is still intact and not burned out. I find that a pair of needle nose pliers makes it easier to remove the fiddly little fuses.
Cable/Wire Damage
Manufacturers do a pretty good job of protecting the electrical cables on ride-on mowers by tucking them well out of the way. But they still haven’t managed to make them invincible from all problems, including critters chewing through them from time to time. If there is any break in a part of the electrical cabling/wiring circuit, then you won’t hear the click sound.
Inspecting the Cables/Wires
I find that the easiest way to check the cables is to carry out a visual inspection. This works for those cables that you can see are in good shape. On the other hand, you need to test the cables that are tucked away or the ones you are unsure about. Luckily you have an electrical tester/meter. The easiest way to test if there is a break in a cable/wire is to carry out a continuity test. This will identify if there is a break between both probes. So, if you place a probe on one end of a wire and the other probe on the other end, the meter will tell you if you have a break or if it is ok.
Connections & Terminals
At the ends of all of the cables and wires, you are going to find some form of connector or terminal. This is going to include places like the battery, the back of the ignition, the fuse holder, and the connections of the starter solenoid. If there is a loose connection or a corroded terminal, this can cause breaking the starter circuit and stop the relay from activating.
Checking Connections & Terminals
This part of the diagnosis can be done using two methods. The first is a visual inspection, then a voltage test. So, start by looking over all of the connections to make sure that everything is connected correctly and that there isn’t any corrosion.
Then, take your voltmeter or multimeter and test the voltage on either side of the connection. For example, the voltage tested directly on the battery should match the voltage tested on the connecting terminal. If there is a drop in voltage, then you’ll have discovered a problem with the connection. These two tests can be carried over the whole of the starter circuit.
Checking the Starter Relay
The starter relay is basically a switch for the current needed to turn a starter motor. The large amps needed to start an engine (cranking amps) would very quickly burn out an ignition if the large amp were passed through it. Because of this, a starter relay is used. As the starter relay is activated, it makes a clicking sound, or at least it should.
Testing the Starter Relay
To test a starter relay, all you need to do is give it power. To do this, you can use the battery that is installed on your lawn mower. Now, different lawn mowers use different relays, so you’ll need to know what type you have. Some relays could have four connectors, and some could have more.
If you don’t have a manual, then you can trace the incoming wires to work out what is positive and what is negative. You need to make sure that you know which side of the relay you’re testing. So, once you have figured out what the connection is, you can go ahead and power the relay.
Once the input terminals connect to power, you will hear the click as the relay activates. If there is no click, then you’ll know it’s definitely faulty.
5 Solutions to Fix Riding Mower That Doesn’t Start with No Clicking Sound
Once you have been through the electrical starter system and found the problem, you’ll need to move on to the fix. Here’s what you need to know to carry out the fixes for each problem.
Battery Charging
Charging a lawn mower battery is pretty straightforward as long as you know what type of battery you have. Charging a battery using the wrong settings on a charger can be potentially very dangerous and result in a battery exploding. So, be sure to use a charger compatible with your particular battery. If you are unsure, I recommend you remove the battery and have your local automotive store take a look.
Once you have a charger that matches your battery type, all you need to do is connect the positive to the positive and the negative to the negative and then start charging. Whenever I know somebody wants to charge a battery I always tell them to check their owner’s manual for the battery information and check the charging procedure. This is because some batteries need to be disconnected from the mower’s electrical connections first.
Tools Required to Charge a Lawn Mower Battery
- Correct Battery Charger
Ignition Replacement
The first thing you need to do is remove the positive connection from the battery. This is going to prevent any unfortunate electrical mishaps, including damaging your new ignition.
So, once you have the battery disconnected, you will need to remove the old ignition from the lawn mower. Usually, the ignition is held in place with a few clips on the back side that can be removed using a small screwdriver.
Once the clips are removed, you should be able to pull the ignition from the mower with the cables still attached. I find the best way to deal with the cables is to remove one at a time using a pair of needle nose pliers and connect them to the new ignition. This saves getting the cables mixed up.
Once you have swapped out the cable, you should be able to feed the new ignition back into its mounting position on the mower and reattach the clips. Finally, reattach the battery and give the ignition a try. Hopefully, you’ll hear the click once again.
Tools Required to Replace an Ignition
- Replacement Ignition
- Needle Nose Pliers
- Screwdriver
Fuse Replacement
This is probably the quickest fix on the list. All you need is a tool to remove the old fuse, which you probably already used when you discovered the burnt-out fuse. If not, then again a handy pair of needle nose pliers should do the trick. Just be sure that when you replace the fuse you use the right rated fuse. Don’t be tempted to use a bigger fuse as this will lead to other problems in the future.
Tools Required to Replace a Starter Circuit Fuse
- Replacement Fuse
- Fuse Removal Tool (Pliers)
Cable Repair
If you have discovered a damaged or snapped cable, then you need to evaluate the best approach to repairing it. I would always try to replace the entire cable whenever possible, but this can depend on the situation. If the cable is part of a wiring loom, then it’s probably easier to splice the cable back together.
So, again disconnect the battery and grab a pair of wire cutters. What you’ll want to do is cut out the damaged cable so that you are left with only the good, undamaged wire. Then take a butt connector and mark up how much of the wire sleeve you need to remove from each end of the wire.
Once you have it marked, use a pair of wire strippers and remove the unwanted amount of wire sleeving. Then, place the wire into the butting connector and crimp with a pair of crimpers so that it’s nice and firm.
Once you have one end complete, go ahead and do the same to the other end. To finish off, use some electrical tape to weatherproof the new connection, then reconnect the battery.
Hopefully, your repair will have solved the issue of the missing click.
Tools Required to Repair a Damaged Wire
- Wire Cutters
- Wire Strippers
- Connector Crimpers
- Butt Connector
- Electrical Tape
Connector & Terminal Repair
To clean up terminals and connectors you’ll need to grab a variety of tools. What you are looking to do is remove corrosion and fix any loose fittings.
For the male connectors, I tend to use a combination of tiny files and some light sandpaper. These few tools are usually enough to get off any grime and rust.
For the female connectors that are loose, I clean them up using the same tools and method, then use a pair of pliers to close the opening where I have a loose fitting. It’s certainly time-consuming, but it’s worth the time if you want to restore the connection.
Finally, once I’m finished, I protect the large connection like the battery terminal with terminal grease and the small ones with a terminal protective spray. This helps keep any future corrosion away.
Tools Required to Repair Terminals & Connectors
- Small Metal Files
- Sandpaper
- Pliers
- Electrical Grease
- Electrical Protective Spray
Starter Relay Replacement
The final fix on the list for a riding lawn mower that doesn’t crank or click is replacing the starter relay. Again, like most things on mowers, nothing is ever the same. This includes the starter relay. Now I’ve seen Husqvarna starter relays that just clip in and John Deere starter relays that require a socket set.
So, if you have one of the simple click in Husqvarna starter relays, then disconnect the battery, replace the old relay and reconnect the battery.
For you guys with a relay like the John Deere starter relay, you’ll need to grab your socket set. For these relays, you also need to disconnect the battery first so that you can avoid any mishaps.
Once you have the battery disconnected, you’ll need to start by removing the cables from the relay. These are usually held on using a number of small nuts, probably just four if it’s a John Deere.
Once the nuts are removed, you’ll need to remove the relay from the lawn mower. Again, these usually use a small size socket and nut. Next, grab your new relay and attach it to the mower, then connect the cables. Finally, reconnect the battery and give the lawn mower a try. That’s really all there is to it.
Tools Required to Replace a Starter Relay
- Socket Set
- Replacement Starter Relay
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