wires coming out of the back of the kill switch which go to connectors. Either both have connectors or one may go to a ground. Take the wires off at the connectors and touch them together, the wires from the engine, not the ones from the switch. The engine should stop. That will prove that the switch is bad. It's a common issue. Replace the switch and your back in business. The little "U" shaped clip is holding a set of contacts open. These contacts close when you push the button or remove the clip closing the circuit to ground. Over time the rubber gets hard and doesn't let the contacts close. Touching the wires together bypasses the switch and grounds the circuit to kill the engine.