Hi Sukrum

Have attached a link for internal functions of switches from the Holden Classic car spares supplier which may be of help to you. I have wiring diagrams for the 4/4 1970 onwards and a 1980 +8 (all similar) which I can scan in and send to your email address if you wish.
http://www.holden.co.uk/wiringDiagrams.asp

Good luck
Richard

2009 4/4 Henrietta
1999 Indigo Blue +8
2009 4/4 Sport Green prev
1993 Connaught Green +8 prev