Replacing brake lamps in the car for LED lamps: How to Fix a bad quality LED

In a car brake lights are the most often melted by your continued use (apart from the H7 and H4 for which there is not equivalent LED), so when changing LED we reduce electricity consumption (and fuel) and especially maintenance (not usually easy to change bulbs in cars). (If you stumbled here looking for how to change them, here's the answer ).

I do not recommend installing lamps that are not approved, can be dangerous (as discussed below), unless you have knowledge of electronics can meet with burning car . 

I  bought a pair of lamps DX.com  equivalent 9W (thinking then reduce its power equivalent to 5W lumens if so, which rarely coincide with reality announced on that page), the typical 2 filaments 27 / 5W (connection T25 / T-25/1016/1034/1130/1152/1154/1157/1158/1493/2057/2357/2397/7528/3496 / BAY15D), and by placing saw that the light does not worked .


Willing to find out why they failed, disarmed one; this requires removing the cap, desestañando weld points (either with the welder slowly or with a desestañador aspiration); a couple of points at the base of the bush and the two globs of poles ( remember the position, if we invest run contrary ):

Under the cap resistance (in charge of alum least to be connected to the terminal position light), and the other end goes directly to the plate leds, where divider resistors voltage of each panel LEDs stay hidden so they do not burn with 12V.

By examining the connections of light brake Xsara Picasso, I discovered that the bulb was poorly designed (how strange to be Chinese: P) , because they have not taken into account (not sure if all or only some cars passing) that the pole of the stop lamp makes diversion to ground when unchecked, canceling the current position (which does not happen when an incandescent bulb two separate filaments). 
Furthermore, we see that the original strength was partially burned, so they endure shortly before failure (see picture):

To fix it I put a resistance higher wattage and twice ohms, and to prevent diversion, place a diode (with 100 ohm resistor to reduce some lumens, making them equivalent to the original incandescent) to the brake light that prevents the current flow in the other direction, avoiding to stay off when not braked:

We put the cap tucking cables diode and resistor in its proper pole, soldered to leave the subject as before and we can prove it.

Result: A led bulb for every year you can take the car , saving fuel and battery, and goodbye brake maintenance.