Headlight burned out? Car won’t pass inspection? Or, do you just want to be able to see a lot further ahead on those dark back roads you frequent, so you and Bambi don’t have a coming-together? Well, read on . . .

Replacing your Miata’s burned-out headlights with the OEM sealed beam units, and upgrading them to higher-wattage or European-pattern type halogen units is essentially the same process, so we’re covering them both with these instructions. Since the OEM style lamp is sealed, it is only replaceable as an entire unit, available at most auto parts stores as well as your Mazda dealer. There are many choices for upgrade lamps, among the most popular being the E-code lamps made by Hella or Cibie, which utilize a glass relector unit with specially-designed lenses, and a separate halogen bulb.

These lamps are not technically DOT-legal, so if you install them you are on your own as to passing inspection or ticketing by the police. They do offer a much improved beam pattern and brighter, more focused light with distinct vertical "cut-off" to reduce glare for other drivers. Another similar alternative are headlight units like the Hella "Vision Plus" series, which is SAE/DOT legal, and offers much of the performance of the E-code lamps.

A multitude of various bulbs (H4) are available for the E-code lamps, with higher wattages than the stock 40W low beam/60W high beam arrangement. Again, be aware that higher wattages, like 80W/100W may be illegal, as may the "blue" or "yellow" bulbs that are available. Higher wattage bulbs may be annoying or "blind" other drivers, any may overtax your stock headlight wiring harness, causing blown fuses or worse.

A very good source for Hella products and information is the Susquehanna Motorsports webpage http://www.susquehanna.com/susq/index.htm Although all of these instructions assume that you have an M1 (pre-‘99) Miata, there are also upgrade bulbs available for the M2 "aero" headlights as well.

So, on with the work. Assuming you’ve decided to upgrade your headlights, or need to repair a burned out bulb, here’s what you do:

Step One: Push the "headlight" button (the black one in the center of your dash, with a headlight symbol) to raise the headlights. Leave the headlights and the ignition key "off".
Step Two: Locate the two black cross-head screws on either side of the raised headlight "barndoor", and remove them. There should be a total of four screws per headlight. Carefully remove the black plastic surround from the barndoor. It should snap off fairly easily, once you pry it over the white plastic bosses that the screws thread into.
Step Three: Remove the chrome trim ring that secures the headlight unit into the bucket of the barndoor. Note that in the picture it is the top crosshead screw (one of three) that is to be loosened (not removed), not the larger one below, which is used in adjusting the headlight aim. There should be two other similar screws around the perimeter of the headlight, each securing the trim ring at a "key-hole" slot. Loosen all three screws only enough to allow the ring to be rotated and removed. Hold the headlight as you remove the trim ring, as the headlight could drop out and possibly be damaged otherwise.
Step Four: Once the trim ring is removed, the headlight should be hanging from the bucket by the electrical connector. Note that the headlight unit has a grey rubber boot to help seal the connection. Grasp the black plastic connector, and squeeze the two "ears" to release the connector from the headlight. Don’t yank the connector off, it should come off easily, if you’ve squeezed the ears hard enough. If you’re just replacing a sealed-beam OEM headlight with a new, OEM-replacement headlight, you just plug the connector onto your new unit, and reverse the previous steps, and you’re done.
Step Five: For those upgrading their headlights, here’s a comparison of the OEM sealed beam unit with the E-code H4 halogen headlight. The OEM sealed-beam on the left is somewhat rounder, and as you can see, the bulb is not replaceable. The E-code H4 lamp on the right is shallower, has a faceted glass lense, and a replaceable bulb. The OEM electrical connector and rubber dust boot will fit the aftermarket headlight.
Step Six: Get your new headlight unit out of the box, and see if the replaceable bulb is already installed. In this case the bulb was already installed in the headlight unit. The rubber dust boot has been removed from the headlight unit being replaced, and will be reused. Note the configuration of the plugs on the male connector of the bulb, and verify that the black plastic female connector on your car matches. Note the spring wire clips that secure the bulb into the headlight unit.
Step Seven: Here, we have a replacement H4 bulb, in this case a Xenon gas-filled unit from Hella that is supposed to provide 30% more light than the standard halogen H4 bulb. We’ll see!! Note the pictorial warning on the box, if you can see it, that indicates you are supposed to handle the halogen bulb only by the plug end, and NEVER by the glass bulb end. Supposedly, oil from your fingers which gets on the bulb from improper handling, will cause the bulb to burn-up or fail prematurely.
Step Eight: If replacing the bulbs, as we are doing here, you need to remove the spring clip that secures the bulb, and swing it out of the way. The bulb then lifts right out. When replacing the bulb, be careful not to get anything down through the bulb opening into the reflector. Note that the bulb has three "tangs", which in effect make replacement idiot-proof, in that the bulb can only be inserted into the headlight unit the correct way.
Step Nine: If you already have a headlight unit with replaceable bulbs, then you do not really even have to remove the reflector from the car. Just remove the trim ring and pull the electrical connector. Release the spring clip as shown and R&R the bulb, noting the position of the tangs.
Step Ten: Replace everything in the reverse order that it was removed. You might want to apply some Silicone Dielectric Grease (Note, NOT Silicone Sealant or Caulk!!) to the headlight contacts and rubber dust boot to prevent corrosion problems. The headlight unit, whether OEM or E-code, should have three bosses or raised areas on the back, which register with three corresponding recesses in the headlight bucket, thus insuring that the headlight is installed with "top" up. This is important to assure the beam pattern is correct. The chrome trim ring can only go back on the correct way, as the three key-hole tangs will only line up with the screw holes if it’s on right. Tighten securely, but don’t over-tighten to the point of cracking your new headlight unit!! Turn on your headlights, and check that they both work. If you’ve installed new E-code or other aftermarket headlight units (that is, not OEM-style sealed-beam units), you will need to re-aim your headlights. The aiming of the H4 headlights is somewhat different than standard OEM lamps, due to the very sharp vertical cutoff of the E-code pattern. There are some good instructions on doing this yourself, as well as more discussion and instructions on headlight and driving light installation at the Miata.net "Garage" section, under the heading Electrical and Electronic. See the aiming link at: http://www.miata.net/garage/lighting.html#aiming
I think you will be very pleased with the results of upgrading your headlights. Let there be light!!