So after playing around flashlight modding for several years, I had an opportunity to put my skills to more “practical” use. For a while, I have noticed my door lock/unlock buttons were no longer illuminated when my headlights were on. This did not affect function of course, but I really missed having those lit since it helped to locate them at night, plus looks “fancy”. I figured there had to be a bulb burned out, so I managed to pry off the housing around the door handle and located the bulb.
I flipped over the housing that contained the lock/unlock buttons and found the lamp on the underside. A simple ½ turn of a screw driver and out drop the little bulb and bulb housing. It appeared to be one unit, so I figured I would have to replace the entire thing. The local automotive store did not have them in stock, so it was most likely a special order from the dealer, which we all know usually means lots of $$$$.
Rather than replace it with the stock bulb, I looked into my bag of flashlight modding parts and came across several 3mm bulbs pulled from some cheap off the shelf lights I purchased a while ago. The Vf of these was around 3V, so direct driving them off the car battery (12V) was most certainly kill them (guess how I figured that out?). Using this online calculator, I determine I needed a ½ watt 220 ohm resistor which would supply the necessary voltage.
Next, I tested the polarity of the + and - contacts on the bulb contacts to determine the proper orientation to solder the leads. After a little bit of cutting, bending, and soldering, I successfully tucked the “light engine” into the underside of the door lock housing completing the LED modded illumination setup.
And shockingly, after plugging it in and turning the ignition on, it actually works! There were however, two differences to the stock bulb. The first is this was WAY brighter than the original: easily visible during the day, and killer bright at night! The second was they were illuminated even with the car headlights off (engine still running). I’m not sure why, but perhaps there is enough supplied voltage with just the car running to power the LED, but not the stock bulb.
Anyway, I am very happy how it turned out, especially since it only cost $1.29 for the resistors. With that done, I am going to tackle the passenger side as well.