Engine will not shut off by switch - John Deere 318D SkidSteer

If your John Deere 4600 shuts off when put in gear, even after bypassing the seat switch, there could be several potential causes for this issue. Here are some troubleshooting steps you can take:

1. Check the Neutral Start Switch: The neutral start switch ensures that the tractor can only be started when it is in neutral. If this switch is malfunctioning, it may cause the engine to shut off when you engage a gear. Inspect the switch for any visible issues and consider testing or replacing it.
2. Inspect the PTO Switch: The power take-off (PTO) switch should be disengaged when shifting gears. A malfunctioning PTO switch could be causing the engine to shut down. Check the PTO switch for proper operation.
3. Examine Safety Interlock Switches: There are often multiple safety interlock switches on a tractor, including those associated with the brake, clutch, and other safety features. Check all safety interlock switches to ensure they are functioning correctly. A faulty safety switch could shut down the engine when a gear is engaged.
4. Battery Voltage and Connections: Low battery voltage or poor connections could lead to electrical issues. Check the battery voltage and ensure that the connections are clean and tight.
5. Inspect Fuses: Check the fuse box for any blown fuses. If a critical fuse is blown, it could lead to a shutdown when engaging gears.
6. Fuel System: Ensure that the fuel system is functioning properly. Check the fuel filter, fuel lines, and fuel supply to the engine. Lack of fuel flow could result in the engine shutting down.
7. Engine Sensors: Modern tractors are equipped with various sensors that contribute to engine control. A malfunctioning sensor, such as a crankshaft position sensor, could cause the engine to shut off unexpectedly.
8. Professional Inspection: If the issue persists after checking the above components, it may be advisable to seek professional assistance. A qualified mechanic or John Deere service technician can perform more in-depth diagnostics using specialized tools.

It's important to approach these troubleshooting steps carefully, and if you're uncertain or uncomfortable performing certain tasks, seek assistance from a professional. Additionally, refer to the tractor's manual for specific details about the safety interlock system and troubleshooting procedures.

If you have already replaced the seat switch, PTO switch, and park switches on your Husqvarna and it still shuts off when you move levers out of park, there are a few other things that could be causing the issue:

1. Faulty wiring: Check the wiring harnesses for any damage, loose connections, or shorts that could be causing the engine to shut off.
2. Bad ignition switch: A faulty ignition switch can cause the engine to shut off when the levers are moved out of park. Try replacing the ignition switch to see if that resolves the issue.
3. Low engine oil level: If the engine oil level is low, the engine may shut off when the levers are moved out of park. Check the oil level and add oil if necessary.
4. Fuel system issues: Check the fuel filter and fuel lines for any blockages or damage that could be causing the engine to shut off.

If none of these solutions fix the issue, you may want to take the mower to a professional for further diagnosis and repair.

I obviously am not familiar with the application here but petrol engines have an electrical ignition system that can simply be turned off to stop the engine. However diesels have super high compression that causes the ignition. Diesels with mechanical fuel systems will continue running until the fuel is shut off or the engine is stalled. The fuel is usually supplied to the injector pump through a solonoid valve where an electrical supply is needed to open the valve and the valve springs shut when the supply is removed. The fault is 90% in my mind associated with the this fuel shut off valve. However there is another way that a diesel engine can find fuel to not allow it to stop. A turbo seal failure can atomise engine oil into the inlet manifold and the engine will continue running until all the is used up.

Check the switch on the blades and the arms. One of them osn't working

Have you checked the safety switch under the seat? Operator presence is required on most equipment today to properly function. If the seat switch isn't closed, it will shut the engine down if the parking brake is released and/or the blade PTO switch is engaged. Unplug the seat switch and place a jumper into the seat switch receptacle to the wiring harness; not the male plug to the seat switch. If you can start the mower, disengage the parking brake, and engage the mower blades (with your other switches reconnected) without engine shut down, replace the seat switch.

It won't shut off because even with the switch in off position there's still power from the alternator going to your firing system because a wire has crossed, possibly from heat and melted together at the alternator, and is keeping power from the alternator feeding the wire going to the switch. Start the engine, unplug the alternator, then shut the switch off. You'll see what I mean when the engine dies because the alternator is unplugged and switch is turned off. No problem. Fix the wires.

Sounds like you may be low on oil. Bike runs until oil is pumped on top of engine, and not enough remains to coat the sensor. Engine shuts off, oil returns to reservoir, bike runs again....i guess that's why they call it a motor cycle....

Does this only happen when the engine is warm or at operating temperature or all the time even when cold? In older engines, a 'bad ignition coil' would fail when the engine warmed up and would not start again until cool or at ambient temperature.

Your kill wire from the switch to the coil is bad,disconnected or connections dirty...or switch is bad...try disconnecting the kill wire on the coil and using a jumper ground the coil directly to the engine or frame it should shut down if it does it is the wire or switch do the same at the switch if it shuts down it is the switch..if not the wire has a break..good luck..

Most Honda engines have an oil pressure switch that prevents engine damage due to low/no oil pressure. Make sure there is sufficient oil in the engine and that the wire is connected to the pressure switch.