..ok, with a volt meter set on DC current, at your keyswitch (combi switch), with the switch in the ON position, you shoult read @ 12 volts between the black wire and the green wire...
..the black wire goes to a connector, where it wecomes black / blue stripe and then to a 7 amp fuse...the blk/blu wire also goes to your cdi unit..
..at the fuse, the wire becomes black again, and goes to your fuel gauge, signal relay, horn and at least one stop switch...
..if you have voltage across black and green at the combi switch, i would suspect that the fuse is blown...
..on a long shot, make sure that you battery's negative terminal connection is secure..and on th "ohm" setting of your volt meter, make sure you can get a reading from that terminal to your scoots frame...
...post back!