Wiper Switch: 1959 - 1964 GM Single Speed w/ Washer option - Two Terminals.The single speed wiper switch, compatible with numerous early models, is now available again featuring the push button washer function. This is a brand new reproduction part. NOTE that this has TWO terminals on the back.. NOT 3 like the 2spd switch does which is number 593175 per below. 593175 1959 64 GM Models Windshield Wiper Switch Reproduction windshield wiper switch with correct terminals and shaft for 1959 64 GM models. For use on models 2 speed