I had to diagnose a kill switch the other day. One question, Do those wires still run to the killswitch at the handlebars? Kill/start/stop switch only needs 4 wires.
I haven't opened up an SJ ebox yet so I can't tell you where they go. I did however, test all four wires with a logic probe. If I remember correctly, two of the wires (black and white) are just (+) and (-) and the other two (brown and tan) are signal wires for start and stop. I could have them reversed? If need be I can probe them again and tell you exactly what wire goes where, and what polarity it carries for a given input.
Got any more pics?