Wiper Motor Switch Schematic Doesn't Agree w/the Physical Part? 68 Dart

Do not go by that diagram, it is aftermarket. Go to MyMopar.com and download a 68 or 69 service manual. You may have to settle for Dodge/ vs Plymouth

Also get into the text of chapter 8 (electrical) and read through there's quite a bit on wipers. Frankly I hate Chrysler wipers. The linkage, wiring differences, and documentation are a PITA