John deere SST16 How do I remove and test ignition switch.

This could be a starter solenoid issue. Do you do your own repairs? You can 'bypass' the solenoid but I would not recommend doing it if your not familiar with engine electrics.

check and test the fuse holder tendency to damage and ign switch

Your question is convoluted... is it a no crank or a no spark or both? Both, implies brake switch but can be other.

I find no detailed free wiring diagrams so I can answer only in general.

For engine crank, most ZTR mowers require brake ON, PTO OFF, and both steering arms OUT (ground drive neutral), then ignition switch to start position. Some ZTRs require operator in seat in addition.

As for spark... engine ignition kill shunt circuit will close to battery negative (frame ground) when ignition switch is in the off position, otherwise open at ignition switch. Safety circuits operate in parallel to the ignition switch.

When ignition switch is not in the off position, the following safety circuit conditions will close the kill shunt.

1. PTO on and operator not in seat.
2. Brake on and either steering arm out. (Most but not all ZTRs).

The incomplete diagrams I find show a relay that powers the starter solenoid so verify relay not energizing and trace back through safety circuits. A simple inexpensive automotive test lamp would be a useful tool for troubleshooting.

Is there a button to stop and start blades turning ? if so check that out its in the on postion it will not start .

limited info generic answer pop can be anything check fuse and solenoid --check for spark --fuel to narrow down problem --no spark electrical problem --no gas fuel problem

It requires the following safety states.

Seat occupied
Parking Brake depressed/locked
Mower disengaged (PTO off)
If automatic trans, shifter in center slot.

Is the click you here the solenoid or a safety relay activating.

Check voltage scross the solenoid coil. It should read battery voltage when key is turned to start. If its stays at zero, safety relay is opening or there's an open wire or miswire.

If the solenoid coil energizes, then either the starter positive is not properly connected or starter to ground via engine block (mounting bolt).

When you try to turn over engine with key it turns over slowly and stops? It acts like starters not working properly? If this sounds like it and it's a single cylinder Briggs and Stratton engine ohv's your valve specs are off they need to be checked and adjusted every 200 hrs. If you need further assistance let me know. [email protected] or call 831-578-4034 pacific standard time ( California)

have some one activate it while you feel it if you feel a click or movement its working if not its bad then get a volt meter set to 12 volts ceck the voltage going to it 1 ground 1 hot if its grounded to frame it may have only 1 hot wire when its activated

The starter solenoid may be stuck in the on-position. To check this, on the starter, remove the small wire connected to the solenoid coil terminal. If the starter still runs, the solenoid is stuck on. If rapping it with a hammer doesn't stop it, the contactor pin is welded to the motor contacts.

Sounds more like a bad starter than a bad coil.

A failing coil usually shows up during hot weather. The engine will start and run fine, then when it heats up, it just dies out. After a few minutes, it cranks again. Then the cycle repeats itself.

The ignition module and coil pack are the same part.

Are you sure full voltage is getting to the starter? There is likely a starter solenoid between the ignition key and the starter. These solenoids can be problematic and prevent the full 12 volts from getting to the battery.