jeeez good luck my friend did one of those jobs in his 86 GT, and swore he would never touch another wiring harness again. You should look on the net for tech articles: I did that while converting my center console in my 94.
Good Luck!
------------------
Elisha (Mustang Chick Extraordinaire)
1994 GT/Saleen: GT-40 intake,4.10s, full exhaust, pulleys.
Sold the 1986 LX sedan
http://www.geocities.com/mustangbelle_306