Parts Manual:
http://www.searspartsdirect.com/partsdirect/part-model/Husqvarna-Parts/Riding-mower-tractor-Parts/Model-96025000200/3199/1509200?searchedModel=960.250&blt=
Wiring diagram: (zoom to 200%)
http://c.searspartsdirect.com/lis_png/PLDM/1006648P-00012.png
Jumper white to white on the PTO clutch wires and see if it will turn over.
Result = No check to make sure the clutch / brake pedal switch is being made when you depress the brake.
Next install the Seat switch jumpers black to black and gray to gray for TESTING only and attempt a start.
Last... use a longer jumper and connect White wire of PTO to the solenoid small ( + ) terminal and try a start. If it starts here the clutch / brake switch is bad.
You can do this.. it is not hard. Just a matter of sorting out which switch is not working.
Something to try before installing jumpers... Bounce on the seat pretty hard several times and cycle the clutch / brake pedal through full stroke. I.e fully depressed and then pull it all the way to the top for 5 or 6 cycles. Then attempt start.
Feel free to post any comments or questions anytime. I will respond.
Thanks for choosing FixYa,
Kelly