low coolant light on 91 gt

the low coolant light is on in my 91 gt. i checked the coolant and it is full and green. is it just a bad sensor or sender or could it be telling me something is wrong with my cooling system? i see a little coolant sitting to left under where the thermostat is. everything looks to be in okay condition i am not sure what is leaking. the water level doesnt change but i have this low coolant light on and i do see a little coolant in a spot that there shouldnt be any but it doesnt seem to loose any or smell when driving.

nevermind i fixed it. turns out the sensor in the overflow bottle is what determines if the coolant is low or not and the sensor was bunched up at the top of the bottle where no water was. i put it in properly and the light went off.