2000 articat 400 after about 15 minutes if running the temperature light comes on but the engine don't seem to be to hot the fan comes on soon as the switch is turned on the hoses don't seem hot and after an hour the radiator is still cool the water pump ain't leaking I have no idea what it could be

 

So the fan runs constantly as soon as you turn the machine on? I would start by changing the sensors that control the fan and temp light. Then i would look at water pump and thermostat. They may be both working but not at their full potential and could be just a matter of time before they fail totally