1991 Dodge Truck water in oil light is on

I need to know more are you talking about the check engine light is on if so have the code read and let me know what you have for a code

Is this a diesel? And is it the "water in fuel" light that is on?

yes it is 91 cummings dodge 250.

oh yeah you know the turnbuckle that goes between the steering gear housing and the steering wheel shaft-it connects the two of them together-my dealer in albq has these on backorder like forever. looking for a source for one. dan

You didn't answer my question about what the light says. Also, you said you "flushed" the filter out the bottom. What did you flush it with? this is important. If you flushed it with diesel fuel, the light will go out by itself after a few engine cycles.
A turnbuckle is something with threads on it. If you are talking about the flex joint on the steering shaft above the sector, NAPA or any major auto parts store will sell a rebuild kit for it.

the water in the oil light on the instrument panel comes on. i just flushed it by pulling up on the valve at bottom of filter and let diesel flow through it for a few seconds. will check napa, thought these parts were factory ones.

Did you understand my response?

Yes, It sounds like you have it under control.

I would likle to know what do do so as to turn that light off. do i have to replace the sensor or what.