Thanks Alan, I have one of those Cibie headlights that need a bulb with a window in it's base for the sidelight to shine through, as of the moment I have a Quartz halogen bulb in there that has no window, so no side (pilot) light for now.
what I was trying to get though was a tail light on by itself and stay on when I switch to headlight, to do this with a link wire results in live feed to the headlight.
I think the Lucas switch on the Flash has internal circuits that get around this, this switch doesn't it is not a Lucas or known switch.
The switch has a chip off it inside the headlamp so I think needs replaced anyway so If I can find out a part number I get one.
Spent two very full days wiring the bike, why can't they use the same colours BSA did?. also have added indicators so there's a bit of a full house inside the headlamp.
I like your magneto cut out idea, damn I forgot to run a wire for that, however I did run an earth front to back so I could tap into that.
many thanks for your reply