I'm attaching a picture that has 2 wiring diagrams side by side. The left side is the 2000 Polaris Sportsman 500 (Early) wiring diagram and the right side is the 2000 Polaris Sportsman 500 (Late). The Late wiring diagram for 2000 is more than likely either the same or extremely close to the 2001. And they may have just carried it over (the late wiring diagram). I've got a lot of hours on ATV's and Polaris especially - they stuck with what worked and didn't reinvent the wheel from one year to the next (usually). This may not be exact - but it should be extremely close. Hope this helps. Good Luck.
All The Best, Justin Lee