TailLights

Design & Service Notes

The X1/9 uses a fairly standard taillight bulb configuration, with only single filament bulbs being utilized for the rear lighting- all but one of them being a standard 1156 bulb (or equivalent- more on this later). Running lights are handled by a lower wattage bulb, which is a 5w 5007 (again, or equivalent) . All of these bulbs, or their equivalents, are easily available at Auto Parts stores.

The reflectors are simple molded plastic housings with a layer (although quite spotty, at least on my two examples) of chrome paint. Over time, this chrome finish can wear off, fade, or crumble, exposing the not-too-reflective plastic below. Duplicolor makes a chrome spray paint which can easily remedy this and restore the performance of the reflector housings- though I cannot give any insight on how long this repair will last because, well...it has only been a few days since I have done it. Time will tell. The main (red) taillight reflectors are divided into two, somewhat distinct, sections. The upper section is for the 5w running light and the lower section is for the 21w brake lamp. Using original halogen bulbs, the two lighting zones tend to blur together, so this is not always obvious at a quick glance, especially at an angle. No dual filament bulbs are used in the taillight housings, so this allows us to improve upon the original design quite easily by using bi-directional bulbs which allows for two distinct "lighting zones" in the one housing. Based on the design, this looks to have been the intent to some degree, but it is mediocre at best.

Bulb replacement is simple and only requires the removal of the visible screws holding on the lenses in order to access the sockets. The turn signal and reverse light lenses are retained on one side by the main (red) taillight lens and hinge underneath the main lens during installation. If the lens gaskets leak, moisture can make its way into the housings and rust the sockets. Steel wool or light sandpaper can help restore a good connection- as long as it's not too bad. If you have to fight to get the old bulb out, it's likely a good idea to try to clean up the surface before reinstalling the new one.

Original Specs

Many different bulbs will fit and work in our BA15S sockets, but I highly advise that when using halogen bulbs, you stay close to the original wattage specified for each bulb. In the case of the X1/9, that is 21W for the Brake, Reversing, and Turn signal Lamps. The rear running light (headlights on, brake not depressed) is a 5w bulb, also using the BA15S socket. The theoretical power consumption of the taillights in the original OEM configuration is 10/52w (running lights/brake depressed).

LED Upgrade/Conversion

Modern LED bulbs allow us a lot of freedom to do what we want, as power consumption is not a concern. In my opinion, our stock running lights are far too dim to be safe in a world where car taillights are getting ever brighter. It may have been fine in the 1980s when all cars were like this, but not anymore.

My solution to this was to replace the running and brake lamps with two diode 7506R LEDs. Due to the bi-directional light output of two diode lights, this creates distinct running (upper) and brake (lower) sections in the taillight. The Sylvania ZEVO line of products uses LEDs made my OSRAM, a well regarded manufacturer of efficient and long lasting LEDs.

There are multiple advantages to this configuration, including instantaneous response to brake pedal input (which is much more effective at getting the attention of the drivers behind you), brightness of running and brake lights comparable to cars today, significantly reduced power draw, and extremely long service life. The theoretical power consumption of the taillights in this configuration is 3/6w- a difference over stock which is quite noticeable. Depressing the brake pedal no longer results in an obvious voltage dip, especially when the wipers are in use. For reversing and turn signal lights, I recommend NOT using the two diode style LEDs. There are cylindrically shaped LED bulbs with many low power LEDs that more closely mimics the light output pattern of a traditional halogen bulb, which works much better for the style of reflector used in the reversing and turn signal lights.

Disclaimers:

• There are many bulbs equivalent to the 7506R, including the 1156R. The 7506R was chosen due to its availability locally, and little more. Considering the significantly reduced power consumption, bulb selection really does not matter that much as long as it performs how you would like.
• If replacing the halogen turn signal bulbs with LEDs, be sure to replace the original EL13 equivalent flasher with an electronic one which will provide consistent performance regardless of battery voltage, temperature, and circuit load.
• Using 2 Diode LEDs in the front turn signals results in a much more focused beam that does not shine up and down as well as the original bulbs do. I recommend using the round style, like some variants of the Sylvania 1156A, for this application.