So, we replaced the sensor and guess what? We HOPEd the situation would CHANGE, but the problem remains. Engine temp is fine, seems to come on either with a sagging temp needle or slightly above halfway. I have noticed a lot of fluctuation in the temp gague since I have been watching it like a hawk. I have heard that the thermostat is weak when this occurs. It's probably original. The intermittent low coolant indicator light seems to be the last light to go out after starting the car. The fan motor speed control has been in various positions and I have seen the light come and go. Mostly it will go out it seems , when it is on, if I turn the fan control to the off position , but it is no guarantee. I realize that it wouldn't be instantaneous as there is data to process with the signal before the light is energized. This coolant recovery tank is only a year or so old....Any ideas? Haven't had the heat come on during AC in quite a while by the way.