1972nail wrote:It depends on whether they were Lucas or Cibie lamps. The Lucas ones had both dip and main beam filaments in the outer lamps and just main in the inner. This meant that the current for both inner and outer lamps on main beam went through the dip switch.
The Cibie lamps only had dip filaments in the outers. Switching on the headlamps with the headlight switch sent power directly to the dip lamps, avoiding the dip part of the dip switch. Flicking on main beam just powered up the inner lamps, thus reducing the load on the main beam switch. The dip beam always stayed on.
Snoots were different in that the power still went through the dip switch but only one pair of lamps were lit at any one time, inner or outer, not both. However, many have since been modified to have both on with main beam.
Dearie me, it's more complicated than I thought but combined dip and mains in the outers and additional main beams on the inners sounds workable. For the moment though, just till I get it back on the road, I'll stick with standard setup and definitely look into dip/main combined LED headlamp bulbs in the original lamp bodies at some future date as being the most plug-and-play, least nerve-wracking option.
I already have relays (and midi-strip type fusible links) added years back, and it did brighten up the original lamps a little. One strip supplying a new relay box under the bonnet where the old lucas dynamo regulator was, containing relays one each for dip, main and horn (the horn relay switches the negative side) and individual in-line fuses right after each of these three new relays. Plus another midi-strip for everything else, supplying the original fusebox. So there are no heavy loads through any of the the switches, even the thermal cut-out is still there but could only exceptionally trip/cycle as it only supplies the switches and then the relay coils.
Thanks for the tips!