Tether kill switch

just splice into the kill switch on the bars and then go from their and if that works just disconnect the handle bar kill switch and their u go
 
Splice the tether wires into the black and the black/white wires to the kill switch. The kill switch can be left operatable.

I soldered the tether switch wires directly to the kill switch, makes a neater job and keeps the wiring waterproof.