How do I wire the headlight...

I'm going to finish my DOT mods soon and I would like to know how to make the headlight have a low and high beam.

I thought I could just wire it using the factory switch so that the low beam is the "off" position and the high beam is the "on" position. Does this work or do I need a 3-way switch (off, lo, high?)

I am NOT an electrician and don't know the first thing about electrical stuff. I can follow directions really well, I just can't figure out what is electrically safe or an immenent disaster.

Detailed instructions would be appreciated since the local shop (not where I bought it) was no help.


Pooley It is really quite forward when you understand what you are trying to accomplish.The headlight comes prewired for low beam only. If you are just after a high beam, switch the connector on the headlight to the other spade that is not connected. If you are after hi and low beam then you will have to get a three position switch or a handlebar switch. This will select where you want the power to go. Off, no power. The two other positions will divert power to either the low beam or high beam. You will also need a headlight connector with three prongs. The stock one only has two prongs. Grab one out of an auto junk yard or an autoparts store. You will also need a three position switch if you want to have both hi and low. The stock switch as you found out is only a two position switch. On or off. You need another postion to send the power to the high beam. Your choice is to either buy a handlebar switch from Baja Designs or get one from a bike wrecker off an XL/KLR/ or similar. Or you can fashion some sort of handlebar mounting for a three postion switch found at an electronics store. So once you have a switch you will wire the Yellow wire to the normally closed contact on the switch ( off) (See your manual for a wiring diagram if you need clarification page 6.1 in the 1999 WR400 manual)

The present blue wire will wired to position 1 (normally open) of the switch and lead to the low on your headlight(as prewired) For the high beam you will add a wire to the second position on the switch (ie highbeam also normally open)This wire will run to the open spade on your headlight. The black wire is of course your ground. Make sure you respect the same wiring arrangement on the ground. ie dont relocate its position. If you do it will still work but you will shorten the life of your halogen bulbs.

I hope this clarifies? :)


Thanks fershy. This is exactly what I was looking for. I appreciate the help.

Question to Fershy or anyone else.

Done all of the above to have independant high and low beams. My problem is the following. How do I wire the rear bulb to be on when either the high or the low beam is on.

The rear light currently is wired only to the low beam.

If I now also connect the rear light to the high beam position this will cause both high and low beams to come on at the same time no matter which is selected because the two circuits are now linked via the rear light wiring.

What do I need to do to have independant hi lo and still have my rear light work when either is selected?

Also, why don't horns work with AC current. It looks like I need a battery to get the horn I bought to work correctly. It doesnt even squeak!

I wonder if it's the same issue on the WR450's?


I just installed one of these: Mini Headlight Switch . This switch has a separate wire for the tailight circuit so that it will be on for both the lowbeam and highbeam circuits. If you follow the blue wire from the headlight, you will find it's spliced to the on/off switch AND to the tailight. I had to find this splice and separate it from the lowbeam circuit. Once this was done, all worked as expected. One thing about this switch, however, is their documentation is wrong regarding the wires for the high and low beam circuits. I had to reverse them to get the correct function. This switch has a kill button also but I used that for the horn. :)

I wired my headlight by first replacing the stock connector to the headlight with one that has all 3 wires. Take the stock wire that went to the low beam and connect it to the switch. Now take the wires that go to the low and high beam and connect them to the other sides of the switch. I used an on/off/on switch.

What I wound up doing last year was to leave the original on/off switch in place as a master switch. The output of this I attached to the center of the single pole/double throw switch. The remaining 2 terminals I wired to the individual beams. Only one filament is on at a time and I can even run with the headlight off and still have my tail/brake light with the SP/DT in the center position.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now