Columd mounted switches do wear out& cause many evils.They are held on by 2 nuts on your lower column. Slotted for adjustment. Rod from keyswitch hooks into it &activates it. ALso you have a neutral safety switch with 2 large wires on column that could be your problem. Can be jumpered. Also in a pinch, you canjumper a wire from the large red wire at theswitch & touch to the large purple wire going to the starter, or even run a universal starter push button.