Cooling Fan problems of the 1996 Dodge Ram Van

While driving, could hear wind noise coming through the door on driver's side, continued driving, later, checked door, door lock post where normally welded to frame/covered with sheet metal, came off. Dealer rewelded door post back to frame. Had to be redone again 6 months later. Water leak at rear seam. While cruise control was activated at 68 mph, vehicle accelerated to 78 mph and was climbing. While driving in extreme heat, the clutch fan engages, there is a loss of power, and there is very low fuel economy.