Had another look at the wiring diagram, if your high beam always works correctly, it can't be this ground connection .
The high beam uses the same wire as the low beam .
The only thing between the switch and the headlight is a wire connector on the right side of the backbone tube of the frame at the front of the bike, there are three connectors there, they snap into a sheet metal bracket welded to the frame .
If there is not a problem with the connector (corrosion or pushed out wire end), or any obvious wire damage between the connector and the headlight, the switch may be the problem .
They're known to go bad, I'm on my second replacement switch .
Does the switch have a detent feel to it when you move it ?
Your indicator lighting may just be a loose bulb in it's holder, it's a 'wedge' type bulb, a glass bulb with wires folded over against the glass, no metal base, I'm not real fond of these bulbs myself .