For WPC games after Popeye (not including Popeye)
There's a box inside the coin door to the right. Has a couple plugs in it, one of which comes out and has 12 pins in it.
For US 120v operation, the connector will have the following jumpers set
1-11
2-3
7-10
8-9
Pin 1 is the square pin in the upper right hand corner. It is numbered as follows
240 volt operation is as follows:
1-11
3-9
7-10
Make sure to change the line fuse from 5 amp to 4 amp.
Might want someone in Australia to confirm this, I'm just going based on my schematic manual and could be wrong!
The schematic manual I am using is at
http://www.pinrepair.com/wpc/wpc-95.pdfSee page 3