How to ground PDC?

The speed sensor wires were reversed. Once corrected it ran great.
Also, I made sure the sensor grounds were located on a common stud. And that stud was tied to body and engine grounds.
Cool, can you please elaborate on your sensor grounds? Bear with me, (edit) my harness (97) only has two stock grounds, harness eyelet and AC ground eyelet. Did your stock harness have more than this or did you create these extra grounds. Thanks in advance.