Low Coolant Light Problem

96 GT, after recent heavy rainstorm, low coolant light comes on after a few minutes of driving....coolant level is ok...unplugged wire to sensor, and light still comes on after a few minutes....are there other sensors other than the one on the overflow tank??? What else could it be??? Can the overflow sensor be replaced???

96 GT, after recent heavy rainstorm, low coolant light comes on after a few minutes of driving....coolant level is ok...unplugged wire to sensor, and light still comes on after a few minutes....are there other sensors other than the one on the overflow tank??? What else could it be??? Can the overflow sensor be replaced???
It could be a short due to the wet weather. Check the wires.