Cooling fan issue

..for how long?

If they run for a couple of minutes and then shut off that is normal but if the car is running hot you should service the cooling system.

And it comes on before the van is up to temperature

I believe it runs until you take the fuse out

ok, lets start with the basics, check coolant in the radiator when van is cold, the fan will run when AC is on(automatically when in any defrost mode, if van runs hot it might run after you shut it off to cool it down)check and see how long it runs after you shut it off..