Scarab Wiring
 

Looking for some help! Is there anyone out there that has or knows where I can get a wiring diagram (original) for a '85 Scarab 400. Looking mainly for dash switches and cabin. Not really sure what controlled what on this.

I doubt you will find anything. They do not have really have standard schematics for specific boats.
Boats are wired individually, for the most part, depending on optional equipment. They are wired based on universal marine wire color codes.

Found the standard for you http://boatwiringadvice.com/boat-wiring-colors/