What would a warning light on a 1992 Mitsubishi Diamante that looks like it would be for fluids mean when it obviously is not for fluids because they are fine?

Did you check the windshield wiper tank? I also owne a 92 Diamante, I thought at first that it was my coolant, checked my owners manual it was, like said b4 washer fluid, wich was full, I simply unpluged the sensor, not the pump but the sensor it is the plug on top of the two to choose from, bingo light is out no more worries