Oddjob, The coloured wiring diagram I borrowed off the internet was enough to get things straightened out so thanks go to the artist. I find vintage diagrams are often missing something but the key information for the switch contacts and basic intent dictates corrective action. The wire with the black band is found on various Honda bikes to supply power to the Br/W. Here is one from a CB750.
Oh I know that Rotortiller, I was in the trade for many years and have wired up thousands of bikes from out of the crate, there is one I distinctly remember having a yellow tube on it for some reason, I think the reasoning was to convert the stripe to a yellow from another colour. My point was to ask the OP IF they had this switch and if so then check the contacts on it as that would clearly be the problem, no switch, no problem.
The secret is in consulting the correct wiring diagram. The colored 'aftermarket' ones often cover one market only. Go for example to the last pages of the Shop Manual Honda CB500/550 and learn that the CB550F2 for instance had no less than five different diagrams.
Since I know my model is a CB500K2-ED, I can always check the appropiate data.
As a lot of bikes these days have been exported to outside the market they were originally intended for so that's not always possible, we rely on information from the OP and that info is not always forthcoming, American markets for instance got running lights, most of the rest of the world did not, the UK got a passing light or headlight flasher and a lot of others didn't. However certain fundamentals remain the same for all markets so even the wrong diagram is better than no diagram.
As for coloured wiring diagrams are concerned, they serve a purpose BUT I prefer to use a genuine Honda one, a coloured one for instance is almost useless if you're colour blind but can be useful in certain circumstances, they tend to be bigger for example so people with close vision problems find them very handy.
