Power TO the key switch would typically be from the battery connection at the starter solenoid, through the fuse to the "B" terminal of the key switch.

Power FROM the kev switch to the solenoid would be from the "S" terminal of the key switch, through the clutch/brake switch through the PTO/attachment switch to the SMALL terminal of the starter solenoid.

Well partly fixed. Started tracing the wire from the ignition switch B terminal back. Found a connection corroded off. New terminals and plugged back up and all seemed fine. So I started double checking safeties first by not pressing in clutch,didn't start. Then the PTo but it in gear and tried no start. Then by not setting no start. All sounded great. So I started it up and put it in forward. When you let off clutch petal it starts barley to move and shuts down like a saftey.

What have you done to the seat switch that you shouldn't have?

LOL! I did by pass to check it. That switch is bad. Tore the switch out and wire brushed and still dont work. Cant figure out why. When the seat is sat on it connects. When off it don't. But it still don't complete the circuit. Am i missing something. When jumped it will go forward. But not reverse. And when I push the reverse button some times it lights and sometimes not. Dose that mean the button setup is bad? How can i test? I want all the safeties working as its my Dads.

Without a link to a good schematic, I can't say.

Are you SURE the seat switch closes when occupied?
Many are closed when unoccupied, grounding the kill wire to the engine.
The connector has a "shorting tab" in it, so unplugging it assures you'll have no spark.