You can download factory service manuals FREE at MyMopar. You might check both the 67, and the 68/ 69 manuals. Don't just go to the wiring diagrams, go to the wipers section text in the section 8 of the manual
And 66.
Start by going here first and identifying which wiper and wiring is on your car. Wiper Motor Wires
Then you have a chance of finding more in the shop manual.