I would prefer to have the sensor working correctly too, but I have read on another forum that several people have spent a thousand or more dollars and still not found the problem.
Cummins did check for codes and were not able to find anything Cummins related. They told me that it must be in the Freightliner chassis wiring.
I am in Montana right now and it is cold. When I get further south, I will do as suggested and check all ground connections on the frame.
Thanks for all the help and suggestions...Don
Also, the engine has plenty of power, so it is not being derated because of the low water level light coming on. I'm glad about that:)