Small plug is the connector for the accesory power outlet, the 6 pin one's for the driving lights. There's also a socket with about 12 wires that has a plug in it that just has two little wires that loop back into the plug - that's for the alarm.
As far as I know the light switch is missing from all Triumph bikes (and in fact from all modern bikes). I'm told the wiring's in there for it but can't remember seeing it. "Jenks Bolts" apparently used to stock the switch but the rumour mill has it that the last one was sold about 6 months ago and Triumph haven't made any more.
Matt
