I am not sure if I am the only one who has this problem, it might be so because of the mods I that have been done to the rear tailight.
After finally getting the rear tailight wired up and working, I found I couldn't get both headlights to come on at the same time. Looking at the hyosung 650 wiring harness, it appears the hyosung does not use dual filament bulbs. The hyosung high/low beam function seems to be handled by using two separate lights stacked vertically (you can see this on pics of the 650r/650s). Since the Fisher users two horizontal lights the high low beam only turns one light on at a time.
I attempted to fit some dual filament bulbs but their width makes it really hard with the standard Fisher headlight lenses.
For now my simple solution was to make it so that one headlight stays on regardless (after the bike starts of course) and then the 2nd headlight comes on when the high beam switch is flicked or the passing switch is pressed.
Its pretty simple making this happen, all you have to do is open up the switchgear/riders left hand controls and get the switch out and then make a perm connection via solder on the switch. The switch is set up so the low beam is a circuit between the top/1st white wire and the 2nd/middle yellow wire. The high beam is a circuit of the bottom/3rd yellow wire and and the 2nd/middle yellow wire. I dropped some solder onto between the top/1st white wire and the 2nd/middle yellow so there is always a connection between these two even the switch is flicked to the other setting
NOTE: The passing switch uses the yellow wire so if you connect the yellow and the yellow w/white stripe you lose the passing switch functionality
Right now the switch works fine, when the bike starts, one headlight comes on automatically and when the hi low toggle is flipped the 2nd light comes on. I am now looking for some brighter bulbs for one of the lamps so the high beam/flasher will be a bit brighter.
Just thought I would pass along...feel free to shoot me a note with any questions.
PS this should be the last little bit of maintenance on my bike, finally ready to ride!