please check
Bugman2 and click on the menu link that says "Fan switch". This should show you what you need.
I thnk the switch you have may be more complicated than what you really need. Sounds like you bought a light-up rocker switch perhaps? My guess is that the "positive" contact is indeed for one of your fan switch wires -- in the picture on my site, you'd connect this contact to the yellow wire. The "negative" contact would be connected to the brown wire in this picture. The actual colors of your wires may be different.
here's my bike"
at the front lower left side of the radiator -- that's the fan switch there with two wires coming from it.
The third contact on an SPST switch is usually just to light up the switch. It requires a little more compicated setup than you really want to get into with this project. I don't think that switch will work , at least not easily, for the project.
My advice is to undo the wiring you've done, set it back to stock, then get a simple SPST switch. Then folllow the instructions on the bugman2 web page mentioned. I'm sure it will work out for ya.