looking for wiper switch info

differing voltage (that results in different motor speeds) is in the switch for 3 speed/variable speed switches and motors. 2 speed switch puts out the same voltage in both positions but it goes to different wires - High speed straight to motor, low speed through the ballast resistor on the outside of the motor and that is where the voltage control is (in the resistor, not the switch). If you use a 3 speed switch on a 2 speed motor and use the ballast resistor, I would think there would be a double voltage drop (very low speed?).