Did you make sure the fan motor is actually bad, because on that model, the ECU uses the ground to turn the fan on and off. The power wire runs straight to the fan motor, but it won't work until the ECU grounds the circuit. You could have a bad fan control unit or a bad oil temp sensor.
Also, I think the fans are all the same on the 2000-2002 Rancher. Note that the 2wd, foot shift model doesn't have a fan, but all the other models do.
Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!
You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.