Bi-Xenon 55W Headlight

Winter project time in Ottawa. Fall 2010, bought a 55W bi-xenon HID motorcycle setup kit and this is what you get from the supplier.

Component Mounting

I did the initial install in Jan. 2011, my fingers are still thawing out. Based on wire lengths and available space, I located all components inside the fairing to the right of the gas tank. Fabricated a little platform for the ballast from 1/16" lexan, held by 3 existing screws, two frame brackets and the reflector. Ballast is bolted to this platform.

Wiring is routed along the front fairing frame, held by velcro straps, locating the ignitor below the frame bar. Ground lead goes to an ignition coil mount screw.

Had to cut the middle out of the rubber dust shield. There's a gasket between the bulb base and reflector housing which should keep out water.


The printed instructions were interesting:
  1. "Install the lamp holder to headlight socket and press tightly by spring"

    I believe this means install the headlight holder, re-attach the spring, and it will all be held together tightly. This was straightforward on the Concours.

  2. "when installation the lamp holder, the headlight inside reflector will hold the lamp holder, please disassemble the top of the lamp holder"

    This one is trickier. The lamp holder has a round reflector thingie on the end, held by a screw. I believe this instruction means if this reflector thingie bashes into something inside the headlight housing (e.g. an internal reflector), take the thingie off and throw it away. Then the rest of the holder will fit in. I didn't find this was necessary for the Concours, but I've read that some people discard the thingie to change the light pattern.

Initial Schematic

As delivered, it used a separate fused lead to the battery, isolated the high and low beams with a diode, and used a SPST relay to control the headlight current. I wasn't too thrilled with the power lead running all the way back to the battery post.

The Ottawa winter kindly allowed further rumination. Noticed that other eBay kits did not need the separate battery lead. Figured out that a SPDT relay would get around that and had a spare SPDT relay kicking around in the basement parts pile from a defunct project (fog lights).

Revised Schematic

 So (Feb. '11) I removed the SPST kit relay and socket, pulled out the relay socket connectors, added a connector for the Normally Closed contact, did a bit of cutting and soldering, inserted the SPDT relay and now it should work drawing power directly from the existing headlight connector. The SPDT relay has a mounting tab that fit nicely onto one of the platform screws.

This has its pluses and minuses. It's more self-contained, with all the wiring and components up near the headlight. However, all the current (~5A) goes through the J-Box relay contact. As 55W is the stock design headlight load, and I've had ~7A flowing through there for years running an 80/100W halogen, I'm not going to worry. Now the diode is there to prevent relay coil voltage spikes on disconnect (when switching to low beam) from frying my electronic voltmeter.

Addendum: The supplier has replaced this 55W kit with one which uses a single integrated relay and requires no separate battery or ground connections.


Still haven't tested yet, too cold to run the bike, fingers still recovering from the 2nd install. Powering up will probably wait 'til spring.

Back to Halogen

The HID setup worked brightly for about 4 years. This summer on a trip, it died, and I noticed the absence of headlight in an unlighted tunnel thru a mountain. The front running lights don't really compensate much, and with the mechanical bi-xenon setup, there's no other filament to switch to.

So back to old technology, halogen 80/100W, reasonably bright and if one filament dies, the other is hopefully still avaliable.