Headlight only works when "dip beam" button depres

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Jun 14, 2007
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I don't get it. Something wired backwards?

(What the heck is a "dip beam" switch anyway?)

Newbie? You bet. Thanks folks - BrianK
Also, when I took apart the LH switch to clean it (before which the headlight didn't work at all, so some progress has been made...!), there was a single ball bearing rolling around in the switch when I got it apart. I didn't see where it belongs and can't figure out what to do with it on reassembly. Another mystery, with respect to which any intelligence will be greatly appreciated! Thanks folks - BrianK
Re: Headlight only works when "dip beam" button de

BrianK said:
(What the heck is a "dip beam" switch anyway?)

Dip (dipped) beam = low beam.
Thanks. Ball on end of spring, improves the action of the switch, but still no lights unless I depress the "dip" button, at which point the high beams come on and stay on until I let go of the button. But just having the ignition in the run-and-lights position does nothing to the bulb, no matter which position the two-way toggle switch is in.....
When you say "high beams come on" do you mean both headlamp filaments come on together (high and low beams)?

There should be a *blue* feed wire to the switch, a blue/red from the switch to the headlamp bulb low (dip) connector, and a blue/white from the switch to the bulb high beam connector. Could one of the headlamp filaments have blown? Otherwise there would seem to be a fault in the wiring from the switch to the bulb, or the switch is faulty. If you have to hold the switch on it does seem that the switch contacts are either dirty or worn.

Feed wire to switch should be blue not white.
White wire to switch unit is headlamp flasher feed wire
You do have a toggle on top of the head light right? I hope you have the headlight opened up for this testing. It's hard but your going to need to get a handle on the pathways and don't forget ground. With a bulb in a socket with a pig tail and some clips you should have this isolated and fixed in no time. Once you grog the pathway you may come to the conclusion that that I did. That a wire from each battery terminal up into the head light than branching to three mini relays that the bright ,dim and horn switches plug into works very much better.
Thanks folks. Enough frustration for tonight, I'll go at it again tomorrow! Cheers - BrianK
The UK term for the US "low beam" is "dipped beam". Many US vehicle lighting systems switch to a lower wattage beam when the "dimmer" switch is operated, whereas the Europeans actually change to a filament that's in a different place in the bulb, resulting in the beam actually being focused at a lower angle rather than set to a lower intensity.

On my first car, a 1938 Austin Seven, it was a mechanism to wonder at. In the back of the driver's side headlight, there was a solenoid which physically moved the headlight's reflector to redirect the beam towards the sidewalk and away from approaching traffic. At the same time, a switch built into the system turned the other headlight off.

On a wimpy 6-volt system, I'm amazed anyone thought such mechanisms were necessary. I figured that at any speed above 45 mph, the wind would have blown the lights out anyway.

I did do a "modern" (early 1960s) conversion to double-dipper headlights. I think they were 48-watts, a hell of a load for a 1930s 6-volt generator. After carefully aligning both lights on high beam, I ventured out in the dark a few days later. When I hit the dip-switch, one light went down and the other one started looking for German bombers.
Brian, If you dismantle the switch again and remove the two small cross-head screws that hold the plastic assembly inside the alloy casting you will find that there are a couple of sets of points inside that can get corroded, clean these with emery paper and also check that none of the wires have come adrift at the solder joint. Make sure you dont loose the small springs that operate the push buttons.
Mine seems to feed the headlights through a WHITE wire, which is not carrying any current. I'm in process of tracing that one back through the harness to see where the break is....stay tuned...!
OK, the white should be the supply for the headlamp flash button and horn.

Blue should be the supply to the dip (Hi/Lo beam) switch, which should switch power between the blue/red dip wire, and blue/white main beam wire.
White wire is "switched" power from the ignition switch (hot when switch is on) and feeds the turn indicators and horn into the left side handlebar switch. Blue wire feeds the Hi/Lo beam switch and leads from the toggle in the headlight. This is hot only when the toggle is "on" and the key is in "lights/run" position. Headlight toggle is fed from the Brown/Green from the "lights/run" position of the ignition switch.

Start by checking for voltage at the brown/green at the toggle switch. (Ignition switch turned to "lights/run"). Then move to blue at toggle, then at left handlebar switch. If these all show voltage, then check at the main beam (Hi) and dip beam (Lo) connections. These will be blue/white and blue/red.
It's working! (Sort of...) Cleaned a lot of contacts...found a few connections loose in the harness... replaced the inline fuse with a modern style one....still a bit of uncertainty in the switch (sometimes has to be jiggled a little to make proper contact), but it'll pass inspection and maybe even get me home at night...

Something still a little off - the toggle has no effect on the headlight beam, just the pilot/parking light. Better than it was though!

Thanks very much folks! - BrianK
BrianK said:
Something still a little off - the toggle has no effect on the headlight beam, just the pilot/parking light. Better than it was though!

Could you possibly say how it is affecting the pilot light? As that should not be connected to anything in the handlebar switch unit, so the beam switch should have no affect on it.
The pilot lamp (and tail lamp) should work from the ignition master switch brown/green wire when switched to the lights on position.
Dunno if I'm using the right term. There's a small bulb inside the headlight lens. It turns on and off with the toggle (when ignition is enabled). The toggle does NOT affect the headlight, on the other hand. So it seems something, somewhere, is reversed....
The headlamp toggle switch function depends on the model year as early models originally only had a two position ignition switch that had no lighting control, which meant that the lights could be switched on regardless of whether the ignition was switched on or not as it was wired to the battery side of the Ign. Sw..
This meant that anyone could come along and switch the bike's headlights on if it was parked up! (or the owner would forget to turn them off?) but the toggle switch should work the headlamp in all cases whether it is fed from the ignition switch or not.

So the ignition switch was eventually changed to a type that had a 'lights on' and 'parking' position. The early toggle being a three position switch and the later one a two position switch.
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