Miata Forumz - Mazda Miata Chat Forums - Exterior 99-00 Bi-Xenon Headlight Retrofit

This setup you're about to see may not be quite the same quality/output overall of some we've seen in the past (thinking of Godless Commie's at the moment), however, they are probably easier to complete (no cutting or modification to the housings or projectors required) and the parts are relatively inexpensive while being of very good quality. I highly recommend that while you handle the parts that you wear latex gloves, especially the projector shrouds or any of the chrome pieces. They easily pick up oily fingerprints and when cleaned improperly, can lightly scratch, leaving a hazed finish.

The projectors are $120/pair from TRS, the hardware was $8 (had to buy 100 screws, lol), the relay harness was $30 from TRS, and I ordered some cheap eBay HIDs ($40) so I could test all of this first and not be out a ton of money for some higher quality HIDs. And the donor headlights were provided by a local forum member in exchange for my current housings when I'm done with all of this.

* I assume no responsibility for you screwing up your headlights, getting pulled over, or any other problematic issues you may encounter.

For this project I'm using Morimoto Mini H1 Bi-Xenon projectors (with Mini Gatling shrouds) from theretrofitsource.com. These projectors have low-beam/high-beam capability and include parts to make the retrofit a mostly bolt-in affair.

First, we have the projectors:

https://www.miataforumz.com/attachme...ine=1312294076

https://www.miataforumz.com/attachme...ine=1312294076

Then we have our donor headlight assemblies, remove the rubber boot, bulbs, and unscrew/remove the clip that holds the main bulb in place:

https://www.miataforumz.com/attachme...ine=1312294076

Preheat the oven to 220°, while it's warming up, prepare a cookie pan by covering it with aluminum foil (helps prevent the pan from stinking of burnt plastic, although no odor is really produced). Place the headlight in the oven for 10-12 minutes, I found it worked best to use the rack in the middle. Time will depend on your oven obviously, less time is better.

https://www.miataforumz.com/attachme...ine=1312294076

Put on a pair of soft leather or vinyl gloves and remove the headlights from the oven. Carefully use a flat head screwdriver and pry the lens from the housing, too hard and you'll damage the housing or lens, they're plastic so they get soft when hot. If the housing doesn't want to come apart easily, put it in the oven for a couple more minutes. When it's at the proper heat it will come apart easily with just a little assistance with a screwdriver. The sealant will stretch as you pull the two pieces apart, just let it break, making sure that the sealant doesn't get on the lenses. (Reinstalling the lenses is the opposite of these steps, heat and push back together, but we'll get to that later.)

https://www.miataforumz.com/attachme...ine=1312294076

After removing the reflector lens (it's clipped in) I loosely mounted the projectors in the housing to see what things will look like:

https://www.miataforumz.com/attachme...ine=1312294076

https://www.miataforumz.com/attachme...ine=1312294076

My donor headlight lenses were a little foggy so I started some polishing work on them (3M Restoration Kit, goes in your drill, works really well):

https://www.miataforumz.com/attachme...ine=1312294076

Here's the hardware you'll need: very small M3x8mm flat-topped Philips head machine screws (in stainless) and 7/8" fender washers. The fender washers sit between the projector and the headlight reflector and seat the projector in the correct position. The screws hold the bulb retainer in place and need to be flat-topped so the bulb can be installed properly.

https://www.miataforumz.com/attachme...ine=1312294076

The provided H4 adapter ensures that your projector is straight and level. Here's the back side with the hardware installed (note: the top of the screws may end up being slightly above the bulb mount platform, this is ok):

https://www.miataforumz.com/attachme...ine=1312294076

So now your headlights should look something like this (lens on loosely):

https://www.miataforumz.com/attachme...ine=1312294076

https://www.miataforumz.com/attachme...ine=1312294076

https://www.miataforumz.com/attachme...ine=1312294076

Here's a couple modifications you should do and are recommended by some on HIDPlanet, but are not required. First here's the cutoff shield as sent by TRS (make sure you do not ruin or change the bend in the actual cutoff shield):

https://www.miataforumz.com/attachme...ine=1312294076

Notice that there are 2 "D" shaped holes in the shield, these will throw some light up into the air, so if little things like that bother you, get some aluminum flash and make a block-off plate:

https://www.miataforumz.com/attachme...ine=1312294076

https://www.miataforumz.com/attachme...ine=1312294076

Some people reported that most of the Gen I solenoids and some of the Gen II solenoids were sticking when alternating between low beams and high beams, (these projector units are Gen II and Gen III just came out), but preventative measures never hurt. Here's the solenoid plunger as sent:

https://www.miataforumz.com/attachme...ine=1312294076

Get your drill, both medium and fine grit sandpaper, and sand the tip just a bit, careful not to take too much material off:

https://www.miataforumz.com/attachme...ine=1312294076

https://www.miataforumz.com/attachme...ine=1312294076

Then spray with graphite lube (which is for high-temp use, good here since HIDs create a ton of heat):

https://www.miataforumz.com/attachme...ine=1312294076

Then reinstall the spring, after making sure to stretch it out some as well:

https://www.miataforumz.com/attachme...ine=1312294076

Then reassemble everything.

https://www.miataforumz.com/attachme...ine=1312294076

Now, tear the front end off the car...

https://www.miataforumz.com/attachme...ine=1312294076

...and install the new headlights. The bumper is just loosely mounted and the lenses are not on the lights, so ignore the gaps and fitment.

https://www.miataforumz.com/attachme...ine=1312294076

https://www.miataforumz.com/attachme...ine=1312294076

Here, the lenses are loosely mounted to see how the final product will look (I like these headlights a lot more without the amber cover for the turn signals):

https://www.miataforumz.com/attachme...ine=1312294076

And here's the cutoff after installation, looks like this will work well when it's completed and adjusted properly:

https://www.miataforumz.com/attachme...ine=1312294076

I personally didn't like how the shrouds I had attached to the projectors. They clipped on in three places, were hard to clip on, and seemed to pop off easily. People on HIDPlanet suggest using JB Weld, high temp silicone, or other methods to ensure they stayed on. I wasn't a fan of that, especially when it would be difficult to fix should one of those methods fail. However the most recent generation of these projectors include a revised shroud that attaches via four screws in existing holes in the projector, which is a lot more secure. I exchanged the current shrouds for the new style. I also took the easy way out and asked for a relay harness too, complete PnP.

Old vs. New:

https://www.miataforumz.com/attachme...ine=1312294076

Relay Harness:

https://www.miataforumz.com/attachme...ine=1312294076

New shrouds installed, definitely a much better design for keeping them in place.

https://www.miataforumz.com/attachme...ine=1312294076

Time to seal the rear rubber bulb cover. It's easy, stack three 5/8" rubber washers (find them on the plumbing aisle) onto the back of each bulb and then pop the cover into place.

https://www.miataforumz.com/attachme...ine=1312294076

https://www.miataforumz.com/attachme...ine=1312294076

So now your headlights are ready to go back onto your car (check them one more time with the lenses off to make sure everything is still ok, such as having level cut off lines).

https://www.miataforumz.com/attachme...ine=1312294076

After checking everything, return to the oven and bake the headlights back together. Loosely apply the lenses to the headlights and place one assembly at a time in the oven for 10-12 minutes. Then remove the assembly and push it together as firmly as you can. Be careful where you push as the plastic is now very soft. If you can't get it back together all the way, simply put it back in the oven for a few more minutes. Adding more sealant is not necessary.

My relay is mounted on the passenger side behind that headlight and the main power source for the relay was taken from the fuse block up near the firewall. If you unbolt the box, there's a large red w/ black stripe wire that carries 12v+ when the key is in any position and that's the wire I used. Each ground wire is bolted to the ground distribution block underneath each headlight. Everything else simply plugs in.

I mounted the "slim" HID ballasts under each headlight to the flat portion of the car's body that's in the turn signal area, so this is all the wiring that you can see:

https://www.miataforumz.com/attachme...ine=1312294076

Didn't have much light left for this, sorry for the blurry photo:

https://www.miataforumz.com/attachme...ine=1312294076

This is just a shot of my 4300k HIDs on at night:

https://www.miataforumz.com/attachme...ine=1312294076

I still have yet to take some photos showing the cutoff line at a distance and the high beams, however, the cutoff is very sharp and the brights definitely do their job. This is a huge improvement over the halogen setup and I prefer these over swapping to NB2 assemblies.

Good luck! Feel free to ask any questions as well!