If you're doing a conversion, do you need the new harness or can you just abandon what you don't need any longer?
Here is a good source for manuals. You could get an electrical service manual for the model you are dealing with.
http://www.diyrepairmanuals.com/harl...Fcyf4AodjGIAyg
They have original factory service manuals and electrical diagnostics, police model supplements, parts catalogs, and other stuff for many years.