turn signals not working

Grounding points "for what?" The only grounds in the signal/ hazard circuits really, are the lamp sockets. What you want for that is a FACTORY manual, not the 2 page aftermarket diagrams. Unfortunately, MyMopar does not have a 75 service manual.

You are likely going to have to round up a "repop" either paper manual or "on CD" if you are going to keep the car it is worth it!!