For quite a while, I’ve been looking at the radio in my truck and thinking it would be cool to replace the standard white backlighting with blue LEDs. Now that I’ve finally done it, here’s the write-up on how I did it. Obviously the designs of radios vary dramatically across manufacturers, but hopefully you can get some ideas on how to make your own modifications.
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. As you can see in the “Before” picture, two of the bulbs were already burned out, and they are just plain boring white 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.
The faceplate essentially snaps on to the front of the body. A flat screwdriver easily pries it off. Four screws remove the bottom of the body that exposes the two connectors that interface to the faceplate. Those easily disconnect and the new faceplate can be removed.
The incandescent bulbs were removed very quickly and easily with some solder wick.
So, I purchased some standard 5mm ultra bright blue LEDs off EBay. I got 50 of them for $5. I also bought an identical radio on eBay (pretty cheap) that had a broken CD player that I used as my “test” bench. I actually made the modifications to the faceplate of the broken radio and then swapped it with the good radio when I was done.
One thing to keep in mind is the viewing angle of the LEDs. I knew this may be an issue with this project. The layout of the bulbs was done such that one bulb illuminates two or more buttons and is placed between them. Since the incandescent bulbs basically have a 180 degree viewing angle the light is generally pretty uniform. LEDs focus the light at the top. In my situation, I was quite lucky in that the LEDs were not directly behind the button. Otherwise they would have likely been too bright and very uneven. So the ultra-brightness of the LEDs compensate for the smaller viewing angle, still giving the desired effect.