Years ago, about 6-8 years or so, I made LED lamps for the interior of the car. I bought a variety of bright white LEDS from Digi-key, as well as the resistors needed to tune in the voltage/current for the lighting circuits. I also used failed incandescent bulbs used in the interior lights(instrument dash, door panels and dash floor).
Here is a blog posting from one of my project blogs;
http://myprojectsandstuff.blogspot.com/2013/11/67-mercury-cougar-incandescent-to-led.html
There are a few details as to what I did that includes a couple of diagrams.
Basically what I did was use the failed incandescent bulb to install the LEDs and resistors. The process required removing the glass bulb from the socket(Dremel tools), and clean up the interior bulb base to allow for soldering LEDs and resistors.
I made LED modules for the front dash, driver and passenger sides. The LEDs have worked flawlessly since they were made.
I am considering making a new batch of LEDS, but I am looking into the better(expensive) LED lighting technology.
SIDE NOTE:
I recently found on the internet, cheap white LED lights that could be used for interior lighting. They are made from low quality components because 3 LED lights have now failed.
