Installing the Temp/Fan Speed Backlighting
This part of the retrofit is my solution to the fan/speed and temperature backlighting. Others have tried a neon/fluorescent lamp and driver to get some stunning super-white backlighting. Others have taken out one or both of the stock diffusers and opted for variously aimed LEDs to get the outcome they were looking for. Still others decided to keep the stock bulb behind this part of the Climate Control and call it finished. I happen to like the blue without the red part of the temperature slider lit up. It’s what happens when you put a very narrow frequency emission lamp behind a filter that filters out almost 100% of all other light. Red filters allow none of the Blue light emitted by the blue LED to come through. Some have experimented with white LEDs with good results, but they differ from incandescent lights that emit a wide band of visible light from the lamp. White LEDs often emit blue and yellow sulfides to get a very cold white. They have shown only a slight amount of Red filter illumination, so feel free to experiment with this part of the project.
You can try this yourself. Take a blue LED and fire it perpendicular to the emission surface of the diffuser from the lamp channel. The light emitting surface is the flat part that faces forward behind the slider, and the lamp channel is what I’m calling the half-circle cutout that the stock lamp is supposed to fit snuggly into. Both diffusers will slide out of their pocket and you will see that each side comes together in the middle to form a “U� shape to fit the stock lamp. I found that if you fire two lamps sideways into the diffusers that much of the light is reflected forward and focused behind the sliders. The angle here is fairly critical and when you fire one at various angles into the diffuser, you will achieve the right angle. Mark these reference angle points so that when you dremel out a channel for the LEDs to sit in, they will shine correctly into the “prism.�
- 1) Remove the ribbon wire and lamp PCB. These are going to be replaced with a non-braided copper core wire pair. Cut about 4 inches of paired wire. Trim the positive side of the wire pair shorter so that when you solder on the resistor, it will be insulated from shorting out against the negative side. Use heat shrinking tube to insulate the resistor and that the remaining leads are stepped down to the correct voltage and just need to be soldered to the correct side of the LED array pair. See my previous write-up for calculating the resistor size. Since both of my LEDs run on 3.5 volts max, and they are running in series, the total voltage drop of the two is 7v. If the supply voltage is 13v (peak value), and the difference is 6v, you get [6/.02=300ohm]. Use the closest value. (pic57&60).
- 2) Remove the lower large (LD) and small diffuser (SD). Just take some needle-nose pliers and grab the “toe� on one end and pry from the middle with a small flat-head (pic43B&44B).
- 3) Dremel the top LED housing. Start small and then finish to size once you’ve corrected for entry angle and depth. The dremel bits tend to melt the acrylic as it cuts so be careful about how much melted material collects on the bit or it will harden enough to cut as it get flung around in there. Take breaks to clean off the cutting bit with an exacto-knife. Having a high-speed drill press would be great as long as the bit used isn’t aggressive (pics06,51,45B). At this time, you can cut channels into the sides and back of the SD & LD to squeeze the 3mm LED stems into so that they stay in place (pic46B).
- 4) You should now black out the end of both diffusers so that the Red LED on the LD doesn’t bleed into the SD area (pics47B). Let it dry. Slide the 3mm LEDs into the small cutout below the ones you just Dremeled out.
- 5) Wire everything together (pic48B). Check that everything lights up (pic47B). In theory, the red LED should be biased to the area closer to where it sits. You can check this by lifting up the LD when it’s lifted and check the output to the bottom. Mine could have been aimed down more, but it’s good in person (pic49B).
- 6) Test the output with the faceplate on (pic51B,54,55, &56).
- 7) In-car test. Follow the first part in reverse order to install the CC back in the car (pics61-63&52B).
Author and Copyright ©: Patrick Barrera (Screen name “pIOUs�).
- At least 15 LEDs From: http://www.lc-led.com/View.jsp?idProduct=94
Part # - 500TB4DF
Super Blue (60 Deg.): 1,800 mcd luminosity; T1 3/4 water clear 5mm blue led lamp; forward voltage of 3.5V is recommended. [15 pieces $20.25]
Amazingly enough, I liked these the best. With as wide an angle as they have, their output is near identicle to the 30deg bright one. I recommend them but they're out at the time of this post.
- NEW From: http://www.lc-led.com/View.jsp?idProduct=135
Part # - 800TB4D
Big Super Blue (45 Deg.): 3500mcd Water Clear Lens 8mm ,WOW. (470nm)
($1.42 each)
These should be great for parking lights.
- NEW from: http://www.lc-led.com/View.jsp?idProduct=150
Part# N500TBR4D
Mega-Bright Bicolor Blue (3,000 mcd) / Red (4,800 mcd) LED in a 5mm.
THese would be great for a multicolor setup for those who can't decide which color they like. These are the first multi-color I've seen that combine blue and red in the same LED.
