In a car brake lights are that most tend to melt by their continued use (apart from the H7 or H4 from which there is no equivalent still LED), so changing them led we reduce power consumption (and fuel) and above all maintenance (not usually easy to change bulbs in the car). (If undermost here looking for how to change them, here you have the answer )).
I do not recommend installing lamps that are not certified;they can be dangerous (as we will see below);unless you have knowledge of electronics you can find car in flames.I acquired a pair of lamps to DX.com equivalent of 9W (thinking to reduce then your power to lumens equivalent to 5W if it were so rarely announced matches the real thing on that page), of 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 them I saw that the light was not working.
Ready to find out why it failed, I disarmed This must be removed, Cap desestañando welding points (good with the soldering iron slowly or with a desestanador aspiration); a couple of points at the base of the CAP and the two gobs of the Poles (remember the position, if we invest it will work on the contrary )):
Under the CAP hide a resistance (charge that alum less when connected to terminal position light), and the other end goes directly to plate leds, where each panel of leds voltage divider resistors, are housed so that they don't burn with the 12V.
Examining the Xsara Picasso brake light connections, I discovered that bulb was poorly designed (how strange to be china: p, because they have not taken into account (do not know whether all or only some cars pass) making the pole of the stop lamp offset to ground when not braking, overriding the current position (which happens when it is an incandescent bulb of two independent strands).)In addition, we see that the original resistance has blown partially, so it will endure little before failure (see the image):
To fix I placed a higher wattage and ohm, double resistance and to avoid the detour, we put a diode (with 100 ohms of resistance to slightly reduce lumens, making them equivalent to the incandescent original) for the brake light which prevents the movement of the current in the other direction, avoiding that it is off when we stopped not:
We return to insert Bush putting diode and resistance wires in its proper pole, we weld to quit subject as before and now we can prove it.
Result: A led bulb for all years that can last the car, saving fuel and battery, and goodbye the brake maintenance.
