How to Wire a Lawn Mower Ignition Switch – Latest Tips

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Wiring a lawnmower ignition switch is part of the engine or ignition switch replacement. The ignition switch needs to be attached to five different sides of the lawnmower with wire. These connections make the mower engine start and keep it running. A safe and secure wired connection is necessary between the ignition and those five different sides.

The ignition switch needs to be attached to the mower body first. You can do the whole job done knowing how to wire a lawn mower ignition switch along with the assist from a veteran. Attaching wires with an ignition switch should be done very carefully with following all the safety measurements.

What is Ignition Switch and the necessary Things to Wire a Lawn Mower Ignition Switch

The ignition switch is mainly a part of the lawnmower control system. It is used to activate the central electrical system and connection in any lawnmower engine. You can say the mower ignition switch is the main component for starting the lawnmower engine. An ignition switch needs to be connected with five different parts.

You will see five pins in the ignition switch with which you need to connect those five components. There will be letters to define those pins, and those five letters are S, M, L, G, and B. These letters direct towards those parts with which you need to connect the ignition switch. 

  • B – It stands for battery
  • G – You need to connect this pin with ground
  • L – This pin needs to make a connection with light
  • S – It is for Solenoid
  • M – It should be connected with magneto

Most possibly, you will have all these five parts attached to your lawnmower body and engine. When you wire these parts with the ignition switch, you will need some tools and materials. Those are:

1. Wires – To establish the connection between the ignition switch pin and those five components.

2. Pliers – You will need it to connect the wire with the pin and other parts.

3. A 15-Amp Fuse – For establishing the connection between battery and ignition switch.

4. An Electric Tester – To ensure a safe and secure connection.

5. Rubber Gloves – For the safety of your hands.

6. Goggles – To keep your eyes secure while wiring the ignition switch.

How to Wire a Lawn Mower Ignition Switch – The Step-by-step Process

Wiring the lawnmower ignition switch is not a challenging task if you have the necessary tools and materials. This whole wiring process is either part of the engine replacement or part of the ignition switch replacement. It is the process where you can bypass all the safety switches through a simple and basic procedure.

Once you gather the necessary components, you can start the wiring procedure. The step-by-step processes are:

Step-1: Connection Between Battery and Ignition Switch

At first, you need to identify the positive power side of the battery, which will lead to an ignition switch. There will most probably be a red wire for that, and you need to lead it through the rectifier. After you do so, you will have to guide the wire and connect it with one side of the alternator. 

From the other side of the alternator, you will have to guide that connection through another red wire. When all of these will be completed, lead the wire to the “B” letter from the ignition switch. You need to use a 15-Amp fuse to connect the battery and ignition switch safe and secure.

With the rubber gloves and the goggles on, connect that wire with the ignition switch by the pliers. Use tapes in every connection between wire and other components to stay safe from short-circuit. Your battery will need a ground connection as well. Make sure you did that before the starting of wiring the lawnmower ignition switch with different parts.

Step-2: The Ground Connection

The ground connection is vital for the ignition switch of any battery-powered, gas-powered, or electrical lawnmower. This connection will help to keep the lawnmower safe from sparking or any types of short-circuit issues. The ground connection of the ignition switch is the simplest among all the five connections, and it is the easiest as well.

At first, attach the “G” side of the ignition switch with one side of the wire, and use pliers for the process. Then guide the wire to the material that you want to use as the ground. You can use a piece of soil, as you can’t connect it directly to the surface. 

So, connect the other side of the wire with a strong piece of soil, and it will do the job perfectly.

Step-3: Connection of the Light

The “L” in the ignition switch indicates the lighting circuit of the lawnmower. To establish the connection between the lights and the ignition switch, you need to first attach the “L” with one side of the wire. Then, guide that wire to the headlight’s end, and connect the wire there.

But not all the lawnmower comes with the headlight function, and many users don’t want to use the headlights. It is not mandatory to connect the ignition switch always with the light. You can even connect the ignition switch with other parts like the fuel solenoid as well.

Step-4: Solenoid and Ignition Switch Connection

Connect one side of a wire with the “S” marked pin of the ignition switch. Lead the wire to the single blade terminal connection, and attach the wire. Use pliers for these two side’s connections, and make sure you are doing it carefully. 

When you make the solenoid connection, you need to have the power out of the solenoid. For that, you need to guide the terminal connection to the starter motor. That’s how you can establish the connection between the solenoid and ignition switch.

Step-5: Connection between Magneto and Ignition Switch  

The last connection you need to establish is between the magneto and the ignition switch. You need to connect the “M” marked pin with one side of the wire from the ignition switch’s part. Connect the other side of the wire with the alternator, and it will lead the wire directly to the magneto. 

After setting up all the connections, check all of them with the electric tester to be sure.


How can I wire the ignition switch of my lawnmower?

Wiring the ignition switch of a lawnmower is not challenging if you have all the tools and materials with you. Check all the pins on the ignition switch, and locate where you need to connect those pins. If you are not getting it, take advice from someone experienced in this sector.

Then establish the connection between those pins and the parts from the mower engine and body.

How can I establish a secure connection while wiring a lawnmower ignition switch?

First, make sure you are using the best quality wires with no leakage, and check them before buying. At each connection, use tapes to ensure there are no leakages and stay safe from short circuit issues. Use a tester to check all the connections after you wire the lawnmower ignition switch.


Wiring the ignition switch is part of the engine or ignition switch replacement process. In this case, re-wiring is necessary to establish a connection between the ignition switch and the other components. You can take the mower to any service shop for wiring, but it will cost you a handsome amount of money.

When you know how to wire a lawn mower ignition switch, both your money and hassle can be saved. While wiring the ignition switch, it is mandatory to maintain all the safety procedures. After completing the connection establishing, check them with an electric tester for confirmation.

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