Wiper wiring 3-speed '74 dart sport ?

^^What you need should be in there^^ Look in the Chapter 8 not just the wiring diagrams, but the text section, there should be a few pages on the wipers.

The section in wiring is mostly page 8-165. Also go on past that starting with page 8-168 and beyond. Go to page 8-176 CI-11 which means "connector, Instrument #11" This shows the layout of the switch and it's wire connections.

Because the 74 diagrams are drawn differently than 72/ earlier, I would download the 72 manual from MyMopar.com and copy the section on wipers and compare it. If the same it will be easier to follow