Modern lawn mowers have become quite complex machines that make the task of cutting grass much more efficient. These improvements, however, also come with a number of safety concerns. Safety switches serve the purpose of adding an additional layer of security for the protection of those who operate the machines. In this article, we will discuss the safety switch problems that may be encountered by users of the Toro Zero Turn Mower. Safety Switches generally ensure safe operation with regards to three major areas.
Table of Contents
Brake System (Brake Safety Switch)
The brake safety switch is an integral part of the mower safety interlock system. It’s functionality or lack thereof will determine weather the engine starts and runs smoothly or not. When the safety pin on this switch develops a problem, the Toro Zero Turn Mower nolonger closes the circuit even when brakes are depressed. This causes the engine not to start and run.
Blade System ( PTO switch)
The PTO switch ensures safety by ensuring that blades do not engage under unsafe conditions. An activated PTO switch will cause battery negative flow to the magnito (engine coil) which shuts down the engine in the event of any unsafe condition. Now if any problem develops on the PTO switch of your Toro Zero Turn Mower, you will either have blades that do not engage or or an engine that keep shutting off.
Operator Area (Seat Safety Switch)
The mechanism works in such a way that when the operator sits on the seat and depresses a push button, a circuit is completed between the battery and the engine. This connection is broken when the operator leaves the seat, hence causing the engine to stop. The seat safety switch on your Toro Zero Turn Mower may develop problems when the tiny wires that line the base of the tiny button are broken or corroded, preventing the switch from completing the circuit needed by the engine.
So far we have outlined the three main safety switches you will find on the Toro Zero Turn Mower and the likely associated problems. We will then explore in generality, other problems that you may encounter due to a faulty or defective interlock safety system.
Engine Keeps Shutting Down
Safety switches generally perform two functions. They can either prevent the engine from starting or shut it down after detecting the presence of unsafe conditions. Safety Switch problems are likely the culprit when the Toro Zero Turn Mower engine starts to shut down even without any unsafe conditions present. The seat safety switch is constantly supplied with battery negative, so a defective seat switch will allow battery negative to flow past it and connect to the engine coil, which shuts down the engine. The same applies when PTO switch or brake safety switch are broken or faulty.
Mower Blades Not Engaging
When the PTO switch is actuated, it energizes the clutch solenoid,then the drive belt is engaged to rotate the cutting blades.The problem with a faulty PTO switch on your Toro Zero Turn Mower is that it will stop voltage from reaching the clutch. In such a case, the mower blades will not engage.
A Properly functioning safety interlock system will provide operators, and in some cases, bystanders with an additional layer of protection against the dangers associated with these machines. Defective switches, therefore spell a hazard to both parties. For example, the seat safety switch is designed to prevent an engine from running while there is no one on the seat. So if, for any reason, the operator falls off the mower and the seat switch does not effect the shut down process, this may lead to injury or death.
Similarly, a problem with the PTO switch, which serves to prevent unintentional blade actuation, will make the Toro Zero Turn Mower a hazard and threat to human, animals and the immediate environment. If the mower continues to run blades without an operator, it may hit objects which in turn will harm any person or damage any property in the vicinity.
Engine Not Starting.
The 12v battery positive is supposed to flow from the key switch to the starter solenoid in order to engage the starter motor and raise the engine. In order for the mower to start, that 12v must flow through the safety switches, which is a safety measure that comes by design. Any
problem with one of the safety switches will interrupt the flow of battery positive and cause the starter motor of your Toro Zero Turn Mower not to be engaged.
Toro Zero Turn Mower: Solving Safety Switch Problems
Bypassing/Jumping Safety Switch
Where productivity takes precedence over an additional layer of safety, one may consider the option of bypassing safety switches. While the manufacturer does not recommend this as a permanent solution, it may be a temporary reprieve while you wait to fix or replace your safety switch. Below is a summarized process to help you bypass the seat safety switch.
- Remove spark plugs, disconnect terminals from battery
- Locate the switch under the mower seat
- Locate switch connector and pry it out
- Locate the pins that enable the closing and opening of safety switch
- Remove the pins
- Re-attach the connector correctly. Also re-attach other components
- Restart your mower
Test/Diagnose/Replace PTO Switch
A multimeter will help you to find out if your Toro Zero Turn Mower PTO switch has problems. What you want is to make an assessment of resistance levels between the PTO switch pins. With the switch in off position, one of the multimeter leads must be placed on an “NO” pin, while other is placed on the corresponding “NC” pin (These should be labelled). If the multimeter beeps and displays a reading, it means that there is continuity between the pins.
The next step in the test process is similar to the first but this time you set switch to the “on” position and test the NC pins against the middle pins (ignore the “NO” pins for this part). A functional switch should give you resistance readings right through. If you pick any faults, replace the switch.
Test The Safety Interlock System
The owner’s manual for your Toro Zero Turn Mower comes with an instructional guide on how to test the safety system. This is one of the most reliable ways of ensuring that your mower is “geared for safety”. By constantly following the process and checking the functionality of your mower, you will be able to pick any safety switch problems at an early stage before you damage more components on the Toro Zero Turn Mower.
Riding mowers are complex machines that require due diligence in terms of safety precautions. Statistics prove that before the introduction of these extra safety components, accidents were more prevalent. The next time you want to remove any safety switch, ask yourself if saving the replacement cost is worth risking a life.