Hi
Does anyone out there know for sure how the sensor for the "water in fuel" works. It appears to have two sensor tips and I'm guessing that the water being conductive completes the circuit which turns on the light.
Thanks
Ken

 

That would be the theory of operation.

I have never seem one come on..............

 

Mine haven't come on in 15 years even though I've never drained the filters.
Good fuel is the reason.
Know that they work because they do come on when the connector gets wet from washing the engine.

 

Your dead on...Thats how it works...Mine never has come on either...I guess my bio is ok...

 

Just ask anyone who has bypassed (or removed) their stock fuel filter canister to install an upgrade lift pump and filter combo, then left the sensor wire dangling or not properly sealed off. Every time they wash the truck or it's raining, the dash light goes on.

 

Thanks for the inputs.
I will be pulling my sensor and doing a continuity test on it. More then likely I will be replacing it.
Thanks again
Ken