So I finally got back to my bike this weekend. I cut the wires and removed the 'loom' from the clutch side, just enough to take a close look at my soldering and check the wires were correct. Everything looked exactly as it should - I hadn't mixed up any wires and all my joints looked good. The only thing I noticed was a tiny, barely visible piece of solder just coming thought the heat shrink on the blue/yellow wire from the hi/lo beam switch. I guess my soldering wasn't perfect - a little lumpy - and it must have been enough to make contact with the inside of the bars. I taped the joint and then taped the entire 'loom'. Re-soldered all the wiring, wrapped the bundle in the headlight and....SUCCESS !!

. Warmed the carbs and started her right up. Ahh, I missed that sound over the winter

. Now that speedo is really spoiling the aesthetics. I need to find an alternative.