Can you trace the wires back into the switch, see where they go? I know the GL1000 is a bit goofy, in that you can crank it with the starter button with the kill switch in the "off" position (it helps fill the carb bowls without sending spark to the coils), so that might account for the "extra" wires.
None of the wiring diagrams I'm looking at have two solid black wires going to the switch, but if you can cross-reference on the switch you have, you might be able to figure out what color the other black is "supposed" to be.