I have an LTX1040 that will blow the 20A fuse the second I connect the battery. I keep getting 12v from the fuse holder even with the key out of the ignition. Meaning there is a short. I checked with the ignition switch unplugged, still 12v. After removing the jumper wire that the small engine shop added the tractor now doesn't get power and just blows fuses. They used a jumper wire from the selenoid to the ignition switch. I reconnected the wire that's going from B on the ignition switch to the fuse holder.
I had to edit your original post to understand this more.
20 amp fuse blows when connected to ignition switch, correct ?
Unplugging the ignition switch and the fuse doesn't blow, correct ?
The green wire you showed is a ground. The only reason it would be on the starter solenoid is if that solenoid needed an external ground for it to work.
Your wiring diagram doesn't show a ground to it, but, the part number on the diagram shows it's a 4 terminal solenoid.
The orange/white wire is the correct wire from solenoid to ignition switch.
Also the green ground wire is factory and the correct length to the starter solenoid.
If you are capable, unplug the ignition switch, use a jumper wire to just the "B" on the ignition switch from battery positive.
Using a test light see what terminal has power to it with the ignition switch in the off position.
If you can do this and see where the power is going thru the switch in the off position report back.
The green ground goes to safety switches, headlights, dashboard (delta monitor) and a module which is on the top of the ignition switch, that I can see.