A lawn mower is a simple machine of great use to every homeowner with a yard or lawn. However, there are many components put together in the mower to ensure proper functioning; one of which is the starter and a starter solenoid. The function of the mower starter solenoid is to trigger the mower engine into action as it performs similarly to the electromagnetic switch.
As the mower switch is turned on, there would be electricity flowing through the mower solenoid to activate the starter circuit. An internal switch would connect the circuit positively for electricity to flow and empower the mower starter motor.
However, if the motor solenoid is damaged, the circuit would not be completed and electricity would not get through to activate the motor for mower action. This is where the user would need to figure out what is wrong with the mower if there seems to be no life with the repeated pressing of the start button.
Steps in Testing
There would be a couple of essential tools which the user may require in testing the lawn mower functionality. The mower solenoid is one of the potential components that could be responsible for the non-functioning of the mowing device although other components could be potential suspects too. Having a wrench and a Multimeter would be useful in identifying the problem with the lawn mower.
Step 1 – Locate the Solenoid
The first thing to do in testing the functionality or condition of the mower solenoid is to locate the solenoid. It is usually located near a large red cable which is the positive cable in the circuit. This should be quite easy to identify when the motor cover is removed from the mower engine compartment.
This cable is connected to the battery directly at the junction and the battery cable is connected to the solenoid at the other end. This battery cable is also connected to an electric post. However, there is another large red cable on the other side of the solenoid but this cable leads to the mower’s starter motor.
There may be other wires present in connection to the solenoid but they would not be as large or obvious like the battery cable. This is also known as the starter cable.
Step 2- Careful Removal
Once the starter or battery cable to the solenoid is identified, it must be removed using the right-sized wrench. It is important to keep this cable mounted and properly positioned to avoid mishaps.
Step 3 – Multimeter Reading
The next step is to set the multimeter to a direct current of 20V; then, switch on the power and use the ground probe to touch the chassis before touching the red probe on the electric post. This would secure a complete circuit to generate a reading on the multimeter. The reading which is registered verifies that there is current flowing through the circuit which is in good order. The voltage reading on the multimeter should be approximately 12V.
Step 4 – Reading confirmation
Once the voltage reading from the battery side is registered via the multimeter, the voltage from the electric post where the starter cable was removed must also be read. Hence, the red probe must be removed from the battery side and be positioned at the electrical post for the reading of voltage on this side.
When the probe is properly positioned, the ignition button could be started to read the voltage. The multimeter would register the voltage quantum if there is electricity flowing through the circuit correctly.
The voltage which is registered on this side of the battery must be the same as the voltage recorded on the other side. A no-voltage showing or different voltages from both sides indicate a malfunction of the solenoid which is not working properly. Hence, it must be replaced.
Tips & Tricks
- Experienced and skilled mechanics may test the mower solenoid without using a multimeter. This could involve a gentle tapping of the solenoid surface using a small hammer once the ignition switch is set to the “start” position. Such an action would free off the sticking switch to generate the complete circuit for a proper connection and mower action.
- The mechanic could also use the common screwdriver in bridging the gap between the starter and battery posts. Set the ignition to “on” with a simultaneous touch on the screwdriver to both posts on the solenoid.
If there is a turning over of the starter motor, this is an indication of the poor condition of the solenoid.
- Safety conscious mechanics understand the dangers and risks of electricity in any task involving live wires. Hence, it is wise to use a screwdriver which is well insulated to avoid experiencing shocks when bridging activity happens between solenoid posts.
- Do not touch the screwdriver using bare hands on a bad solenoid; it is possible to experience a bad electric shock or a burn. It is always wise to put on a pair of safety gloves that is fitting for this type of tasks with a high risk. It is usually the experienced and skilled mechanic who attempts this method with full caution to avoid shocks and burns. Amateur DIY enthusiasts should not attempt such methods in testing the mower solenoid condition.
- The lawn mower should always be in neutral mode with locked brakes before attempting any testing procedures on solenoids. This would safeguard users from undesired activation of the mower that could cause personal injuries.
Test a Briggs & Stratton Solenoid Engine
Different brands and models of lawn mowers would have different types of engines and component structure for their intended functionality. The branded Briggs & Stratton lawn mower boasts of a powerful engine which serves as a fuse for the starter and ignition switch.
Once the motor switch is set on, electric current would flow to the solenoid from the battery to the starter located at the engine. A damaged solenoid would not serve its intended purpose with the engine stagnated. No turning over would be noted.
Hence, testing the solenoid is a crucial first step for malfunctioning engines. It helps to have the basics of engines while engaging in testing the engine solenoid even though the testing procedure may take only 15 minutes.
Here, the voltmeter is required in the testing procedure. The B&S engine is placed on a flat and hard surface for more control and ease of testing. The solenoid must be identified and located which is usually on the engine with the red positive wire running out of the battery to the solenoid. The large red wire or cable is an excellent guidepost to the solenoid.
The spark plug wire is then removed to be cleaned as there may be clear signs of corrosion at the terminals. Switch on the mower and voltmeter. The negative lead of the voltmeter should be placed at the corresponding negative post of the battery. The positive lead (red cable) should be placed on the solenoid post with a positive lead that is screwed on.
The voltmeter reading should be checked for 12V; if no voltage is recorded, try tightening the bolt on the battery positive cable. The nut on the solenoid could also be tightened to check the voltmeter reading again.
The negative lead of the voltmeter should be connected to the battery negative post. The positive lead of the voltmeter should be connected to the other post of the solenoid. The switch must be turned ‘OFF’ before it is turned ‘ON’ to check the voltmeter reading which should read 12V. There should not be any reading recorded if the switch is OFF to confirm the functionality of the solenoid. If the voltmeter registers zero voltage in both ‘ON’ and ‘OFF’ positions, the solenoid is probably defective.
The presence of a starter solenoid on a mower is essential to the proper functioning of the mower as an electromagnetic switch is available to activate the mowing device smoothly. A complete circuit is formed with a closed switch when the ignition key is turned ON to have electricity flowing to the starter solenoid.
With a started engine and released key, the solenoid switch is opened up to disengage the flow of electricity to the starter for a smooth engine run in preparation for the mowing task to be executed. Hence, the starter solenoid is a key component in the smooth functioning of the engine with a prominent role between the starter and the ignition.