I recently had similar issues on this unit in a Spin a card. I removed mine and throughly dismantled it, cleaned the circuit boards and rebuilt it . I'm fairly sure there is instructions on correct set up for these on PBRs website. Take decent pictures of it before you begin if in the slightest doubt.
So that you dont tear your hair out, I suggest that you test with a continuity meter on each segment so that you are certain that each one is not making contact - tracking over -with its partner or it will never work. I used alcohol, a magnifying glass and a sharp blade to clean between each one to remove debris and copper particles, etc. Obviously, make certain you dont leave any high spots after this work or the wiper arm could lock up. And a tiny amount of PBR grease or similar on the board to help it along its travels. Worked perfectly for me afterward.