Wiring help 86 510TX

I need help figuring this simple wiring to connect the single wire kill switch.
As is sits now I am receiving nice spark, with or without the thick black wire grounded.
I do believe the orange wire goes to the kill switch but not certain.
I've tried every possible combination and still no go.
The kill switch is brand new as is the wiring to it and properly attached to the handlebars.

Any wiring help would be appreciated.

I found the answer.
I had to use a two wire kill switch to make it work. The orange wire went to the kill switch and a separate black wire had to be tapped into the thinner black wire shown to ground the switch.