Sorry to say this, but the side lights AREN'T LEDs !!! They are actually very small bulbs with small power (1.2W maximum), and they are connected through 2 to for diodes to the wiring. At least that's what I discovered when I gently removed the sealing with a screwdriver.
So the operation was - remove the side light, remove the sealant, take off the bulb, replace with another, put everything back and reseal with hot plastic, put the side light back again, everything's fine now.
Hope this helps !