This is an old Thread but,,, These are probably better than the TB.com wiring diagrams.
86-87 GN Wiring Diagrams:
http://www.gnttype.org/forums/attachment.php?attachmentid=2606&d=1331636638
Also for other diagrams, the Add-on Electronics and Electrical sections:
http://www.gnttype.org/forums/forumdisplay.php?f=13
http://www.gnttype.org/forums/