Just to clarify the above; the output shaft on a standard front wiper motor does indeed rotate continuously.
A rear wiper motor on the other hand (almost always) includes an extra section in the gearbox that makes the output shaft oscillate back and forth through an approx 90° rotation. This can be simplify the mechanism for some Halloween props.
A rear wiper motor on the other hand (almost always) includes an extra section in the gearbox that makes the output shaft oscillate back and forth through an approx 90° rotation. This can be simplify the mechanism for some Halloween props.