If you are talking about the red wire from the handlebar switch on the LT3000 winch # SW1130220 then it connects to the ignition switch on your 2015 Suzuki King Quad 500. Basically, it needs to attach to a wire that only has power when the ignition is turned on. The ignition switch wire that has power with the ignition on is the recommended wire. Use a circuit tester such as # PTW2993 to identify the wire that only has power when the ignition is on. I have included a picture showing the... view full answer...