Hi Bob,

If your existing setup is a manual kill switch only, and you wanted to add a remote kill switch (RC-100 or other), then yes, you would need to cut into the wiring harness on either the red or black wire (not both). The RC switch wires would then splice into the area where the wire was cut. Hope this clears things up but if not respond and I will try and elaborate further.

Regards,

Kai