It probably needs a wiper switch. Pull straight out on the stalk and separate it from the wiper switch and column. If the stalk knob doesn't turn easily, replace the stalk, otherwise, the switch is probably seized. You can try cleaning and lubricating the stalk, or spray some aerosol electronic tuner cleaner with contact lubricant into the switch, as the case may be, to see if either will free up. The process can be messy because of the lubricant. And... the white lettering on the stalk washes off easily with the application of any type of solvent.