Chaps,
I had a look inside the headlight shell of my Euro 4 spec bike today. The wiring is different to the pre E4 shown in this thread. The ‘plug’ is not there to be pulled. The little ‘thingy’ that I thought might be the new version of the plug is clearly not, as it makes no difference to the lights function when removed.
As others have said, if you remove the plastic blocker that locks the switch in place, all you achieve by ‘turning off’ is turning off the main beam function.
Here’s the real issue:
The left hand handle bar switch has 9 wires going into a block connector. The receiving block connector that’s part of the main loom, only has 6 of those 9 wired in!
So, 3 wires required for full switch function are ‘missing’.
My conclusion is that Pre E4 bikes were wired up to allow normal lights on / off function. Then the factory added an over ride which, when removed, returned normal on / off function.
However, the E4 bikes appear to have a main wiring harness that’s purpose designed to not allow normal on / off function. I even swapped out the handle bar switch for another, still no change. So to change an E4 bike to normal on / off function would appear require interfering with the bikes wiring (something I’m certainly NOT prepared to do).
However... for those worried about the current draw issue, you may consider an LED headlight bulb of the type sold by Paul Goff. I have just fitted these to my ‘68 Bonnie and ‘74 Cdo and they’re great, really bright with a fraction of the draw of a halogen bulb.
However # 2... Shorai batteries like to have the lights on before trying to start the engine as some current draw helps to warm up the battery. So, for Shorai battery users, the auto on lights function is probably a good thing. As a Shorai battery user myself, I’ll take this as an excuse to leave my headlight as is!