wiring in a low/high beam headlight

I was looking at my wiring tonight comptemplating a low beam hi beam switch for the imminent traffic stop I forsee in the future. The Big Gun exhaust seems to draw the attention of the D boyz! I was surprised to see that the high beam is actually the output on our bikes. I would have thought it to be the other way around, just having the low beam operational. Looking at the wiring schematic, it looks like the yellow is the live lead, black, the ground and the blue being switched to provide juice to the tail lights. I have found acquired another three prong headlight recepticle but I can't figure how I am going to wire it so that both high and low supply power to the tail lights without power feeding back both hi and lows? Need I to put a flow switch inline or am I missing something obvious?



Anyone that has gone through the bother of doing this mod themselves?

I am going to bed now, with the problem still unresolved. i hate when that happens!


ps I am wiring this AC rather than DC.

[This message has been edited by fershy (edited 03-22-2001).]

What do you have in the way of a headlight switch? If it its just one on or off switch then you will need to run another switch in series with that one eg. a single pole double throw so to get a high/low beam, also make sure when you wire up your new head-light plug that you copy the old one so that you get the earth in the right position, as you can cause a halogen globe to yellow if the earth is mixed up with high beam.

Splint, I do have a handlebar switch with provisions for off, low beam and high beam. It is a three wire affair. Power in/ power out low/ and power out high. On the WR the blue return is activated when the switch is on. The problem I see is that if you wire that to both the high and low recepticles with that blue, you effectively have power flowing to both filaments at the same time. Somehow the power can not be allowed to flow back either by way of an isolator ( diode?) or some fancy wiring that has escaped my rudimentary electrical knowledge! Good oint on the ground, I will make sure that it remains in the right postion.


Fershy, from the notes I have the wires you need are green-low beam, yellow-hi beam, blue, which goes to your tail-light, I think you should have a power in wire for the switch as well, which could be blue or yellow. You shouldn't need or use a diode as you will get voltage drop over it resulting in less light, but I'm pretty sure that your head-light switch should have four wires going to it

1. power in

2. tail light out

3. low beam out

4. hi beam out

I have converted mine with no problems....

I used a switch unit as used on gas gas trials bikes. I also wired an ac horn and brake light too, as the switchgear has the button.... Also, if you look at the plug on the back of the headlight bulb, you will find that it flips open, and you can slide in another terminal for the low beam. I got one from a car headlamp socket, and it slid right in.

I used the yellow wire as common "power in", the switch has a separate wire out for the tail light, so as not to link hi and lo beams.

The horn is wired with the live constant, and switches the ground.

the yellow wire was split to feed lights in, horn, and brake light.

I bought the switch from a local off road bike shop JAM Sport. Farnham, Hampshire UK.

It makes a very neat setup.

God bless you Derek Burns! I took apart my switch this morning and you are absolutely right. There is a forth wire that serves as a return for the high and low. the circuit is definately separate so it will not feed both hi/low at the same time. Finally some closure to this dilemna. Splint thanks for you comments as well. Much appreciated.


Glad i could be of help.


Hi Derek, what horn are you using that works ok on the bike's ac, a typical street bike horn or something else? And, does it sound normal?

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