OK to start with, resistance or continuity checks prove very little.. To test for voltage at the solenoid, disconnect it, turn key on, and using test light (12V ) or multi meter (Assuming you have one, since you claim to have checked all switches and solenoids, etc.) set on DC volts , red probe (or test light probe) to the wire that hooked to solenoid (the wire that does not bolt to the engine, if there were 2) and the other end to battery negative (-) post and see if it shows 12V or the test light lights. If it does, then you have 12V to the solenoid, and likely have a bad ground connection. If not, then you may have a blown fuse or simply a bad key switch (which would also explain the no spark without coil wire unhooked)
As I see youve gone offline, I'll switch this to Q&A and we can work on this as time is found.
OK. Now, we will *repeat* this test , however - This time you will turn the key to the "Start" position , and see if you get continuity. (Note: The engine may begin to spin over, so be watchful of being near the spinning flywheel! - Optionally you can disconnect the starter cable from the starter or unplug the solenoid wire from the starter) - If you do, then a starting circuit switch (if not the key switch itself) is causing the problem , But If you still show no continuity while the key is turned to "Start" position, then everything *should* be working as it is supposed to, and I would then say , hook it all back up and see if engine starts.. it should, if it started and ran with the ground wire unhooked from coil. If it does not, then something really is not making sense.. (Or, the connector plug itself that plugs tractor to engine harness may be bad! Try inspecting it and see if there's any melting or discoloration..)
OK.. Lets look at how the ground circuit operates (in most cases, cant tell for sure without a wiring diagram for your machine) - When operator is in seat, opening the seat switch, PTO disengaged, clutch pedal depressed, and key to run position, all circuits to ground for the grounding circuit are open. If operator leaves seat with the PTO on, or with the parking brake NOT set (which typically holds the brake pedal down) the ground circuit will complete through either or both switches when the seat switch closes .
So.. Basically you need to first test making sure operator is in seat, brake depressed (for starting) and PTO switch off. If there is continuity to ground, one of those switches is not working properly. If you sit in the seat and let off brake pedal, there should be NO continuity to ground (likewise with PTO switch on) because the seat switch interrupts the ground circuit. If that is not the case, seat switch is bad.
If continuity to ground is gone with operator in seat, then everything *should* be working normally. - if not, then seat switch is still completing a circuit somewhere, or it is shorted, or one of the wires is shorted.
Its difficult to be accurate without any wiring diagram information, though.. if it comes down to it, I can opt out and maybe a Canadian expert can take it over, if they have access to wiring diagrams for that model.
I believe you can upload it to JustAnswer and link to it here, or alternatively you can upload it to a file sharing service I believe - we're not permitted to provide email address or contact information here. it should be a paperclip icon just above the response reply box where you type replies (I think)
That would be helpful for sure - 2000 ohms means you have continuity in the circuit, although there is a resistance, you won't want 0 ohms either (indicating continuity) , but instead want the display to be "0L" or similar. (same reading you get with the probes not touching anything) . Also keep in mind that holding the probes bare ends in your hands can also result in a false reading, so don't touch the metal probes when holding them to the circuits.. (I can hold bare probes in my fingers of each hand and get a reading of .589 MegOhms resistance just from the conductivity of the human body)
and finally, make sure and "zero" your meter by touching the test probes together and reading the ohms resistance reading, which you subtract from any readings you do get from circuit testing.
But if you can get a diagram uploaded somehow, it would be extremely helpful.
Best bet would be take photos and upload the photos to photobucket.com (its free) and then you should be able to link to them in here. Alternative is a file sharing site such as http://www.keepandshare.com/htm/free_file_sharing.php It would be simpler if I could just write out my email address, but it'd be a violation of the website rules.. Or you could run a bing search on my username, find my website and contact form and go from there as well.