I don't know if this has been made before. I decided to make one because I wanted to make something myself because I find it gives me a sense of achievement.
I was motivated to make this because I hate not being able to find the key hole for my car, this is not only annoying but you can accidentally scratch the paint on your car. (I don't have central locking)
Step 1: Things you will need / Ingredients / Materials
> 5mm LED (colour of your choice)
> Small 4x2 LEGO brick (colour of your choice)
> Switch or momentary on switch (I used one of the small square ones because they are easily found and easy to use)
> Small gauge wire
> Soldering iron and solder
> Hot glue gun and glue sticks
> A key ring (I didn't use a key ring but used some thick electrical wire)
> 3 mini cells (I got mine from a A23 battery)
> Some way to hold the cells (see pictures)
> Dremmel (Not necessary but useful)
Step 2: Step 1 --- Lets get started
After the brick is hollowed out you will need to make a hole at one end for the LED. I used a 5mm LED so I used a 4.5mm drill bit, just to be sure it was a good fit.
After the brick has been hollowed and a hole made for the LED you will need to decide where you want the switch to go. I decided to put mine on the side.
I did a dry fit just to make sure it would all work, it turned out to be a good idea as I had the switch around the wrong way.