is there any way to test it? and where do I hook the 2 terminal wires coming off the switch? do I just replace the jumper wire that they have in the middle going from + to - with the 2 leads coming off the switch?
Yes.
There might be a loose wire lead with a eye terminal to fit a cable clamp bolt,if so ,put it on the + of the right batt.
Make sure the tractor is in neutral(it might have a
neutral safety switch,which could also be defective if the SP switch turns out to be OK).
Then try the key to start,It should activate a solenoid in the SP switch(you can hear it snap)If it dont work,have some one turn the key(or jam it in start mode) and test(test light or DVM) on the SP switch if you got power to a small stud(don't know wich one but it should be a single wire)Might want to test for power on these studs before turning the key.(should be none)
If you do get 12V on the small stud with key in start mode and the SP switch solenoid stays silent or clicks but wont turn the starter,the problem lies within the SP switch
If you don't get 12V on one of these studs,tatch jump it from the + on the right batt(The one with the - master disconnect switch in the cab)
If that activates the SP switch and the starter turns over,the problem lies in the wire to or from the key switch or the starter over ride switch or in one of these 2 components.or the neutral switch as mentioned in
boldif there is one.
BTW,check the fuses.
Hope this helps