My light was on forever, figured it was a bad sensor. While working on some other stuff up top I rebuilt the fuel bowl and cleaned all hoses and connections and replaced the sensors and the pre-heater. After all that damn light came right back on. Odds of getting a bad Motor-Craft sensor are low. Anyone have ANY ideas? Also I always run additive (used to use power services but now use the one from Ford) and open the drain valve for a few seconds about every 1000 miles or so. Even then light still comes on!