The electric cooling fan on my '99 v6, 4x4, does not work. Is this a standard part or a factory item? I cant find any mention of it in threads or my owners manual. It has the usual clutch type belt-driven fan as well. I would think it should come on when there is high heat, or any time the a/c is turned on to push more air past the condenser. Any thoughts where to start trouble shooting the problem?