The CRF250X 2006 has a totally different Wiring Diagram and there is no Plug for the Optional Cooling Fan. I just spend and hour looking for a Plug and finally looked at the Wiring Diagram in the Manual and discovered that the 2006 is wired different than the 2004 and 2005.
So I cut the Cooling Fan wires and wired it directly to the Battery and i have a toggle switch with no radiator sensor (which typically burns out anyway) and it works like a champ. I mounted the Toggle Swith near the gas tank petcock so i can reach down and turn on the fan at will.
Thought you guys might want to know that there is NO PLUG IN ON THE 2006 MODEL.