Gah. It’s me again.
On my 2002 Escape, the low-water warning light is on almost all the time. The water level is fine, according to a Ford service bulletin (about 1" over the seam in the degas tank), and yet the light stays on anyway.
The degas tank in this car has a built-in water-level sending unit. Is it possible that over 7 years and 140k miles in seering Sacramento heat, the sending unit is simply haywire? It’s a $60 fix.
Or should I look for something else?
Your hypothesis is a very reasonable one. I bet the sender is just a switch. Check for continuity at the connector, remove some coolant and try again. I hope that you are not using water in your cooling system. You might have a wiring harness problem. I don’t know how much I would spend to fix a sensor that is not really needed. Just find the wire to the light and sever it. Check your coolant now and again the old fashioned way.
I put in the new tank. It works great – no more light.
Pleased.
I think there may actually be a leak, though. But at least now when the red light comes on, the car actually means it. Under $70. Job takes 10 minutes. This problem is noted all over on Ford and Escape forums, and this is the only known fix.
OTOH, after 142k miles, who am I to complain?