Mower won't turn over

You bridged the two terminals on top of the solenoid & the engine cranked then the ground contact is reasonable.
If you jump to the orange wire & the engine cranks then the ground is OK. and the solenoid is OK
This is why you then have to go and check the wiring in the mower.
From memory you already changed the ignition switch so that is ruled out.
This leaves the PTO, Clutch/brake & reverse if you have a manual gearbox.

Can a bad diode have anything to with a no crank situation? Also, how is the starter grounded?

excalibur2 said:

Can a bad diode have anything to with a no crank situation? Also, how is the starter grounded?

Click to expand...

Once again,
The cranking circuit & the ignition circuit are two different animals.
Nothing in the ignition circuit will prevent the engine cranking with the exception of a totally stuffed ignition switch.
Nothing in the cranking circuit will prevent the engine firing , again apart from a totally duff ignition switch.

Your problem is in the loop red wire through to orange wire

Starter grounds through the mounting bolts to the engine and the contact patch where the starter body touches the engine crankcase.
Engine grounds through the 4 mounting bolts.
On some slow cranking engines I run a ground wire from the main ground a the starter motor mounting bolt.
Generally these are mowers that live out in the weather

I have power!!! No idea what the issue was though. Tonight I had the entire harness on my workbench, the only thing I did before reinstalling is remove a couple of the metal terminals from the ignition connector, they are a bit tricky to find the tab to bend them back and slide the terminals out. Once out, i sprayed them with electronic cleaner and scrubbed with a toothbrush. Funny thing is they really didn't look horrible. Reinstalled the terminals. Removed terminals from fuse connector, did the same with the spray. Tightened the metal tabs that hug the 2 fuse blades, one was not very snug. Cut end of orange wire off where it connects to the solenoid, stripped to clean wire and crimped on a new ring terminal. Reinstalled harness, solenoid, battery cables, starter cable, switches and heard this funny cranking noise I did not expect! Wife was getting concerned the last 2 weeks with me acting like a mad scientist in the basement. Now to change the oil and give her a good scrubbin and will return to buddy. Thanks a million for all your help and patience! Just wish I knew exactly what it was that I did tonight that made the connection.

...I still say there was a gremlin in there

Removing terminals & replacing them cleans the contact area.
Obviously the terminal on the orange wire was bad.

Only 1 thing really matters, it goes Brooooom

Ok perhaps I celebrated a bit too soon. When I got it to crank, the tractor was in my basement so I did not go all the way to see if it actually started. So yesterday I got it all back together, pushed back outside, changed oil, etc and went to start it. Cranks fine now but no spark whatsoever. Tried another coil I borrowed off another rider, still no spark, which leads me to believe the issue exists in the thin black wire going to the coil, any suggestions as to how to troubleshoot this wire? There are no bare spots on it so not sure what else it could be.

Remove the thin black wire
It is a kill wire that connects to ground.
If you have a spark with it removed then you have a safety switch problem.
If you don't get a spark with it removed check the black wire for voltage .
If you have put 12V down there for even the smallest amount of time you will have fried the magneto

Not sure what you mean by " If you have put 12V down there for even the smallest amount of time you will have fried the magneto"

Can you describe a scenario ?

I did test both magnetos on the ohm meter, both read around 4.65 which I think is good. In the meantime I'll test for spark with the ground wire off.

excalibur2 said:

Not sure what you mean by " If you have put 12V down there for even the smallest amount of time you will have fried the magneto"

Can you describe a scenario ?

I did test both magnetos on the ohm meter, both read around 4.65 which I think is good. In the meantime I'll test for spark with the ground wire off.

Click to expand...

YOU CAN NOT TEST A SELF CONTROLLED MAGNETO WITH AN OHM METER AND SOME CHEAPER ONES CAN ACTUALLY FRY THEM

The kill wire grounds out the micro chip in the magneto.
If at any time you have accidentially connected the kill wires ANYWHERE in the mower's wiring to 12 V, you can fry the chip.
For this reason, workshops always back test connectors so there is no chance the probe accidentially bridged a power wire with a magneto ground wire.
You will not see or hear this happen, the tiniest of sparks, then the chip is burned out so no further sparks.

This is why coils are not returnable.
I had a customer who fried 4 of them ( $ 300 worth ) before he brought the mower in for repair at the shop up the road.
They sent him to me ( gee thanks ) and I finally found a cross wired brake switch.
I have known customers using $ 5 mulitmeters, fry magneto chips when doing OHM testing because the meter sends power down the probe and measures the voltage drop at the other end to determine the resisitance ( ohms ).
For this reason I use a test lamp or a volt meter because the voltage function is passive and simply reads the voltage either side of a really big resistor in the meter.

Not trying to be insulting, but blokes buy a multimeter who have less than zero idea about how they actually work, then go shoving the probes everywhere where they should not go and at worst end up totally confused and at worst, do real damage to the mower.

Electricity is very simple, however it is taught very poorly and because of the litany of funny names, and the insistance of using the water in a pipe analogy most blokes blank it out.
At best they remember the Ohms law triangle so they can answer a few exam questions then blank it out of their minds forever.
Parents never buy children electronics play sets because they think having their computer literate kids wearing a smart watch than can run the TV of the internet will not be amused by joining up some wires and hearing a radio station so children never understand the basics.
The nephews built a calculator with ferrite loops and were over the moon when they managed to get it to add subtract and even better multiply.
And believe it not not, the one with really bad maths ended up in the top class because he finally got into his head they multiplication is nothing more than repetative adding and division is repetative subtraction