Full wiring diagrams are in the service manual. Free download from this site, along with some color re-makes of a PORTION of the 68 wire harnesses. Beware those color links. As pretty as they are, they simply don't get them all, and frankly I don't find them as easy to read as the original diagrams in the service manual, but everyone is different: http://thefirstgensite.com/html/librarydex.htm