6v BA15 LED headlamp bulbs?

[JonE]

In an earlier posting it was explained that sidelights and headlights are achieved with single filament bulbs by switching the lamps in series to give a 3v output (sidelights) and parallel to give a 6v brighter output (main).

Was just searching for that thread. I notice that the wiring diagram from 1925 shows a single wire and refers the the button to do what Stuart refers to above. This later one refers to R510s, and has the twin wire to the single bulb, but seems to suggest that the current flows in to either dependent on selection of full or side? This must be determined wholly by the dash panel unit switch presumably?

Would I be right in thinking that the later switch panel thus isn't ideal for retrofitting R510s, as it will be issuing different orders from the switch to the later R47s?

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