Secondary set of headlights on a Miata

http://keith.miata.net/lights.html



NOTE: Please don't try this if you're not comfortable working with wiring. Electrical fires are not fun. This is an old page I put up years ago and I would probably do things differently now.

Barn doors. Air brakes. Pizza boxes.

These are some of the names for the stock Miata pop-up headlights. Some folks love them, others will spend large sums of money to replace them with lower profile pop-ups that sacrifice performance for looks. Wouldn't it be nice to have the best of both worlds? A set of lights so low profile that they are invisible until turned on and don't need to pop up at all, as well as a set of lights capable of hurling photons down a dark road with abandon? Read on.

This modification puts a set of standard low-beam bulbs in the place currently occupied by the turn indicators. They're activated as part of the parking lights - ie, by the first setting on the standard light switch. The turn indicator bulbs are moved to a section of the front lens that is unused on North American cars. It's used for parking lights on the European lights.

Inside the car, everything is 100% stock. There's no new switch required, as the normal headlight switch turns on the new bulbs. UPDATE: To be kind to other drivers, I have installed a switch that allows me to turn off these extra lights and run without them.

Some common concerns are related to the heat output of the new bulbs. The reflectors have a metal insert inside that serves to shield the plastic from the worst heat. I've experienced no problems so far, and am monitoring the situation. There's a lot of empty space around the new bulb, so I forsee no difficulties. UPDATE: the only heat problems I've experienced have been with the turn indicator bulbs. Since I have Canadian DRLs, they're running all the time. In serious heat (ie, over 30C) this has caused some melting of the housings.

The new low beams aren't a substitute for a good set of regular lights. They do, however, provide sufficient light for driving around the city where there already is ambient light. They'll look as bright as normal headlights to other traffic, making you visible to others. Basically, you'll have eliminated the need for pop-up lights in the city. Once you're on the back roads, you can raise the big lights. This is great if you have high power bulbs in your pop-ups.

Keep in mind that while this may fulfill the intent of the law, your local police officer may not be impressed. I've had no problems, but proceed at your own risk.

Enough! Let's do it!
Bits required:

* 9006 halogen headlight bulbs
* connectors for 9006 bulbs
* 1156 single filament bulbs (look like the regular turn indicator bulbs)
* sockets for 1156 bulb - I used a generic one
* 30A relay (I used the one that came with my Crazy Red horns)
* spade connectors
* some extra wire
* fuse block
* any snap together electrical connector - as long as it carries two wires


Tools:

* drill
* wire cutters
* pliers
* soldering iron (optional)
* wire strippers (optional)
* Dremel tool (or files)

First, pull the lenses out of your car, along with the wiring harness for the bulb. Put the headlights up to do this. The harness is held in with a fastener to the area under the headlight. You can remove the turn signal harness connector by pushing the connector towards the rear of the car. The plastic pin stays in the sheet metal and the outer three wire connector half has a square recess for the pin's head. (Thanks to Miq Millman for this tip). The harness is also held in by a clip at the other end - you'll have to push down on the tab to get this loose. Now carry the whole mess into the house.

Let's start with the electrical stuff. This is going to be a little confusing at times as I'll try to explain things using layman's terminology.

There's one way to avoid cutting your stock wiring harness. I understand Moss Motors has a "twilight lighting kit" that puts the running lights in the outermost compartment of the lens assembly. If you get a set of these your life will be simpler, electrially speaking. Click here for a wiring diagram, courtesy of Nathan Hornig
If you understand this diagram, just build it. If not, read on...



First identify the wires involved in your harness. There should be three: black, red, and green. Black is the ground, green is the turn indicator, and red is the parking light. Easy enough, right?

Now the commitment. Snip the three wires, close to the lightbulb socket. You'll be attaching them elsewhere. Give the socket to the cat to play with. Take the bulb out first, and keep the big o-ring as well. For the more ambitious, you can keep the socket and modify it to hold your new 9006 bulb in place. The cat will have to settle for something else.

Start wiring up the new turn indicator socket. Easy enough - just attach the green and black wires to the new socket. You can choose your own method of attachment, whether it be butt connectors, solder, or whatever. It doesn't matter what colour wires are coming out of the new socket. Do this to both sides, and set one aside - you're done with it.

Now the relay. Attach the red wire from the harness to the "86" pole of the relay.

Attach a new wire to the "85" pole of the relay. You can splice this into the one on the harness, or attach it to the car body later. If you've got coloured wire, black is a good one to use.

To the "87" (switching) pole of the relay, connect a wire to act as a power supply. I attached my fuse holder here, with an extension so I could reach power. Put a spade connector on the end of this one.

To the final pole (30 or 51) on the relay, attach two wires. One goes to your 9006 connector, the other (about 2 1/2 feet long) goes to your electrical connector. This latter wire is carrying power to your other light bulb, and you need the connector so you can get everything actually in the car.

The loose wire from the headlight connector needs to be attached to a ground. So does the second wire for the connector that's going to the second bulb. These can be attached to the body of the car somewhere - I used the radiator surround, as you'll see later.

Over on the other side of the car, attach the two wires coming out of your headlight connector to the other end of the plug you added in to the relay (two paragraphs above).

Clear as mud, right? Okay, the explanations leave a bit to be desired. If you're not comfortable working with electrical stuff, though, you should probably have some help.

You'll notice that on the stock lens assembly, there's a very obvious place to put a second bulb. You're going to drill this out, and enlarge the opening so it goes to the outside of the little fence around the edge. Here's before and after for you. This is messy. Little bits of plastic everywhere.



I used a drill with a big bit to get started, and then a routing bit on a Dremel tool to enlarge the hole to what I needed. If you don't have a Dremel, you can file down the edges or spend a bit of time carving with a knife. The exact shape is not that vital, but the hole needs to be large enough to let you get the new bulb through.



Now you can put the bulbs in. I re-used the o-ring from the original socket around the hole for the headlight bulb. I haven't yet come up with a great way to hold this in place - my prototype has a series of rubber bands. The other socket attaches with a couple of screws in my case. The yellow electrical tape was a stopgap measure for development. NOTE - The assembly with the relay should be for the left side of the car. I'll get a photo of this mess next time it's out of the car.

Now you've got a couple of lens assemblies and a nest of wires. Let's head back to the garage, shall we?



Get the hood up on your car, along with the headlights.

Where to get power We're going to take power from the handy blue plug that can be found on the right side of the engine bay, as you face the car. It's near the diagnostic connector. As you may be able to see in the photo, it's possible to put the spade connector inside the removable lid for this connector, giving you a handy disconnect should you so desire. That's the fuse holder in the photo. I used a 30A fuse, which is probably too high. You only need 10A to run those lights.

Okay, feed that mess of wires in through the holes in the front of your car. Again, the relay goes on the left side of the car - which is the right as you face it. That's the same side as the power connection, as you can probably imagine. Slip the wire with the connector for the left-hand bulb to the side so that it goes in front of the radiator.



You need to attach your ground somewhere to the body of the car. I used the bolts along the front of the radiator - they're handy for that wire. You can either wrap the bare wire around a bolt and tighten it down, or be a little more subtle and use some sort of ring connection.

Snake the power wire up close to the power supply and plug it in. Connect to the stock wiring harness again. Install the other lens assembly and connect the plug that joins the two sides together.

Once all plugs etc have been joined up with their respective mates, make sure everything is tucked away. Pay close attention to the wires that are underneath the headlights - leave enough room for these to retract without hitting wires! This is important!



Right - do a quick check that everything is connected, secure, and ready to test. Here's what should happen:

* Hazard flashers: the outside bulbs blink
* Parking lights with the ignition turned off: nothing
* Parking lights with the ignition on: the bright bulbs light up
* Turn indicators: outside bulbs
* Daytime running lights (for Canadian cars): outside bulbs
* Headlights on: the bright bulbs remain lit

Now clean up, and go for a drive! Remember, you're nice and visible at nighttime now, but the light is not focused the same way as for headlights. Don't depend on these new lights to see on the back roads or even dark city streets. That's why the popups are still there.

I get a lot of mail asking what extra advice I have. Basically, you substitute higher wattage bulbs at your own peril. If you run anything hotter in the outside spot, you're almost guaranteed to melt some plastic.