I have never seen a 2 wire Kwikee step. They all have 4 wires. Unless Fleetwood had a special step built by Kwikee for them.
1. RED large wire is the POWER (12 volts)
2. The WHITE wire comes from the On/Off switch
3. The YELLOW wire comes from the Ignition side of the key switch
4. The BROWN wire comes from the Pin/magnetic switch in the door frame
5. The Large GREEN wire that is not to the 4 wire goes to the Chassis ground.
So, you should have the 4 wire pigtail that has the short wire ends that connects to the 4 wire harness to the step module. That means you do not have to cut any wires.
Now, there was one model Kwikee step built for Van models that had just 2 wires, BUT, that step had a 6 pin rocker switch that you had to manually extend and close the step. It was NOT automatic when you opened and closed the door. IF that is the step you had, you will have to run the wiring per the instructions and then install the 4 wire system. Yes, cutting the wires would negate the warranty because the do not make the same motor for the 4 wire steps. I do not think they make your type step system anymore. Doug
