Kilogauss writes – “Project to change the backlighting on a car radio to use blue LEDs. I originally wrote and posted this on my blog and can be found here. The radio is the Delco AM/FM/CD model that appeared in many GM models anywhere from 1996 – 2002. The buttons and labels on the faceplate are backlit with a number of 12V incandescent bulbs. I initially set out to do a direct replacement of the bulb on the circuit board. In the end, the implementation was a little different. Due to the space constraints, right away I knew I would need to find an LED with an integrated resistor. They do exist, but they are quite expensive and I could not find any in blue. So at this point the best thing to do was to remove the incandescent bulbs and glue the LEDs into the faceplate, creating wire leads to solder to the circuit board.”Link.