"water in fuel" dash light

Assuming the light goes out on its own without you physically draining the bowl I'd lean towards electrical. Could just be water getting into a wiring plug in the rain and causing connection problems. I'd start with physically disconnecting any plugs in that circuit and checking for evidence of water intrusion. I'd smear a little dab of dielectric grease around the plug body when you reassemble it too. Also check for missing or damaged seals in the plugs too. The water sensor more than likely gets unplugged every fuel filter change so the seal is susceptible to going missing. I'd physically inspect the wiring to that sensor as well. Maybe give the wires at the plug a gentle tug. Most 14-16 gauge wires should be able to stand an 8-10 lb tug. If it can't, then the wire was broken and it was just insulation holding it together.

 

Probably water intrusion into the sensor connector. It is usually plugged into a frame mounted water separator filter such as the Davco or Raycor depending on what you have. Unplug it and smear some dielectric grease into the connector.

 

Where is the sensor located. I just went through a nice sized puddle this morning and it kicked mine on

 

I have international Prostar 2016 eith Cummins and water in fuel sign coming up. Did you find the sensor connector