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.