Installing a new projector headlight in my Ducati ST4s

I have always had an issue with the lighting on this bike since I got it. The previous owner had put HID bulbs in the stock housing. This did not work. The low beam was non existant (wrong focus) and the high beam was too high. I put Halogen lights back in the buckets and added relays to give them they voltage they needed to work as good as they could. But they were never really right because the stock low beam bucket was hacked some to make the HID bulb fit.

HID bulbs need to be in housings designed for them. I found a projector that would work in my bike, replacing the one that was stock. Since it is designed for an HID bulb the focus is correct and will give a proper pattern and good light.

I also learned a little about HID bulbs since removing the bulbs fromn the stock housings on my bike. HID bulbs need good current on start up. Yes they draw less wattage when warmed up, but the have a large surge current when starting up. The original owner had just wired the HID bulbs to the stock wiring. OK for current draw when warm, but inadiquate for start up draw, which explains why on occasion the low beam would not start when I started the bike up. The fact that I have already put relays in for my headlights which are wired direct to the battery with 12 gauge wire will help me here.

The first thing you need to do is get the headlight assembly appart so you can replace the projector assembly. I forgot to take a picture of splitting the housing. It is held together with srews and some glue. I used a utility knife to cut through the glue and then a screwdriver to pry the housing apart

After you are in the housing you will need to get the light housing seperated from the adjusters. There are three of these clips holding the assembley together, there are easy to squeeze with a pair of needle nose pliers so they will release.

Here is a picture of the stock projector (left) next to the new HID projector (Right).

I bought this from The Retrofit Source. They have ready made kits for cars and motorcycles. Since I already had the relays installed on my bike I was able to just buy the projector, HID bulb and Balast from them for my project.

This projector ids a Bi-Xenon unit, it is a low beam and high beam in one unit. HID bulbs do not like to be turned on and off quickly. So to make one unit work for both they mount a shutter in the assembley which blocks some of the light from the beam for low beam operation. When you activate the high beam the shutter is moved out of the way giving you the high beam.

The new projector is smaller than the stock one, so I had to make an adapter to make it fit the stock assembley.

I made a paper pattern first.

I bought a steal plate from Home Depot (a Simpson tie plate) and transferred my pattern onto tape on the plate.
This is the new projector mounted back up to the Stock assembly. I was able to make one plate across the top of the projector and used a single piece of steal to hold one bolt on the bottom so the new projector is held to the assembley in three places.
The hole in the stock plate for the adjuster to mount prevented me from mounting the new projector in four places.

If you look close you can see a hole on each side of the new projector in the middle of the assembley. This was the middle of the old projector. I used those holes to line the middle of the new projector up so it would be pointing in the right place when I put this all back together. (there are marks on the new projector on each side in it's middle)

While I had this all apart I did notice that the H1 HID buld seems to have it's arc chamber in the same location as the filiment for the stock H1 Halogen bulb. It might be possible to put an H1 HID in the high beam bucket and have it work. I left the stock halogen in for now.
Here is everything all buttoned back up and ready to go back on the bike.

I forgot to take a picture of where I mounted the balast. I used outdoor rated two sided tape and two zip ties to mount it to the underside of the bracket that holds the instument cluster.

I also split the power to the High beam bulb so not only does the stock bulb light up, it semds the signal to the low beam side to operate the shutter to activate the high beam for that Bi-Xenon unit.

The new bulbs lighting up the wall.
I gave myself a scare. After hooking it all up I turned the key on to see the results and nothing. I even tried the high beam and the old light didn't do anything either. Then I remembered I had pulled the fuse for my wiring so I wouldn't accidentally short anything while working. I put the fuse back in and all was well.
I have been on a couple of short rides just to see how things look (it has been in the 20's here in Colorado after the sun goes down) and so far I am very happy. This has been a great improvement.

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