Trouble shooting a dead wiper motor

A '68 A-body came with two choices, a 2 speed, and a variable speed. From the photo, it's not a 2 speed, but, it also doesn't look like the '67-8 version of the variable speed one either. Maybe more photos showing the whole thing? Your switch (assuming it's the original) will tell you what you should be using. A 2 speed switch will 3 positions.....off, low, and high. The variable switch will have the off position and then on with a lot of potentiometer range twisting from one end to the other. It will feel similar to the light switch dash light dimmer. Post some number off the switch and wiper motor and maybe we can figure out what you're supposed to have.