I thought the button was a TEST button, to check if the system is charging. I don't think there was any point in a dipping headlamp with a black out mask. In fact I'm fairly sure that dip switches were deleted around the time of the four position WD light switch. Ron
Maybe I wasn't very clear in my question, so there is the '4 position light switch (test-off-T-H) under the saddle. And there is the push button on the headlight panel. (And im looking for the puch button.)
Some extra info cause I have already studied the light switch itself, and the nice thing is that the test function (turn left) is self-returning. So you have to hold the button to the left to enable the test function. This connects the D of the dynamo in the switch directly to the rear light, so it must light up when the dynamo is working!
The other 3 positions are the same as the normal military light switch.
(just see you standing next to the bike, holding the switch, revving the engine and looking at the tail light :D)
Hi Ben. I was aware of this late war economy system and the description on Rob's site clears it up in my head. I thought you meant the push button as a headlamp dip switch. But of course it switches from pilot bulb to headlamp bulb. This would then save the cost of an ammeter and about two meters of cable.
Obviously to do the test, you must first back up to a wardrobe mirror. :smile:
At some point they even deleted the press button Ron
I seem to remember discussing a theory about the completely blank panel, it allowed a replacement standard headlamp to be fitted to an early machine with the switch panel in the tank.
it seems that the test (test-off-T-H) switch under the seat i have is working the same way as a 4 position (off-T L H) switch would that is fitted in the headlamp, im thinking mine has the wrong switch cam fitted, im trying to find a picture of one to se what it should look like,