Temp Display - Back light blue led upgrade

[cypress]

DIY for replacing the boring factory incandescent bulb for back lighting the temp display. This is from a W201.

Pic1 - Display removed, incandescent bulb removed. Opening for led bulbs shown.

Pic2 - Tried 3 types of blue leds, the smallest ones shown the best results. The small led size allowed the them to be placed further away from the display...therefore no bright spots.

Pic3 - Replaced onboard current limit resistor with 220 ohms. 3 leds in series dropped 9.5V, wanted 18mA. (13.5V - 9.5V = 4V, 4V / 18mA = 222 ohms).

Pic4 - Blue leds installed, you can see the leds sticking out in the opening. The outer leds are spread outwards for even light distribution.

Pic5 - Blue leds turned on.