I have a 2003 F250 Ford Superduty 3/4 ton 4 wheel drive, 6 ltr pickup. On a recent purchase of diesel fuel, I fould that the fuel had been infiltrated by water from storm water in the area where the fuel station was located. I went to a nearby Oil and lube service where they drained the fuel from the two filter locations and replaced both filters. Shortly after leaving the facility, the symbol on the instrument cluster re-lited. I was away from home, so I continued to drive the vehicle using the fuel down as low as possible before a refill. This did not help. Upon returning home, I took my vehicle to my normal mechanic. He dropped the tank and drained all of the balance of the water/ fuel and replaced the upper and under cab filters and added about 6 gal. of fuel. By the time I had driven about a mile. the Water in Fuel Light relit.\r\nWhen I arrived home, I decided to disconnect both batteries in order to possible reset the Water in fuel light. I did this and the reattached both batteries. Upon cranking the truck and idling about 2 minutes the water in fuel light reappeared. What else can I do to correct the problem?