So first you will need the reading light, I got mine from the Dollar Tree, your local dollar store might have different stuff, but these ones already came with batteries, a switch, a clip and everything so they were perfect.
The only other thing you will need is an electret microphone, some wire, a female 1/4″ phone or XLR jack, and maybe some aluminum tape. You can get an electret mic from radio shack for like $3, and depending on how much you want your project to cost either a female 1/4″ phone (cheaper) or XLR (more expensive) jack from radio shack also, or you could shop around online.

Anyway now you want to take the light all apart. Just unscrew the top, and use a tiny screwdriver to take the bottom part off.
Then just snip off the LED, solder a couple of wires to the two battery terminals at the bottom, and hook up either your 1/4″ or XLR jack.

You’ll then want to solder the mic on, be careful because it does matter which way it goes, make sure to align the positive and negative terminals correctly. Also the reason I solder the mic last is because you can ruin it with your soldering iron if you apply the heat to it for too long.

After that you just gotta put it all back together, I used a piece of poster putty to hold the mic in at the top to keep it from rattling around, another thing I did was use some aluminum foil tape and wrapped it around the flexible part to shield it, it’s kinda expensive though so if you have a better idea go for it, I just happened to have some so I used it.

That’s pretty much all you need to do to make a cheap recording mic. You could also add a capacitor and resistor to the circuit to keep the switch from popping when you turn it on, but good luck trying to fit it in the already tiny space by the batteries, of course it might fit at the top where the mic is. If you want to try here is the website that I got most of my information from: http://www.epanorama.net/circuits/microphone_powering.html

Below is a picture of what it looks like, as you can see the wire on mine got severed.
If yours is broken at a different place and you can’t use the original cord, no worries, either use the cord from an old junky pair of headphones. If you don’t have an old pair of headphones go to your local dollar store and buy a cheap pair of headphones for a dollar and use the cord from those.

The minimum amount of tools you’ll need to fix the cassette adapter are wire strippers, a phillips screwdriver, and a soldering iron + wet sponge/napkin/old cloth/etc. Plug in the soldering iron now so it gets hot enough by the time you need to use it, and make sure to keep it away from anything that’s going to burn or melt.

Alright so the next thing you wanna do is use the cutting part of you wire strippers and just cut the wire at the part where it’s damaged, if you’re using a wire from a pair of headphones you can skip this step.

Now use your screwdriver and take out all the screws, mine had four in the back and two in front. Yours might be different though, I have another one and it has five screws in the back only.

And so here’s what it looks like when opened, make sure you don’t lose any pieces when you open it. I almost lost a tiny metal bar on the floor when I first opened mine, I didn’t even hear it fall out. I also took apart a Panasonic one a long time ago and it had all kinds of pieces in it that were a pain in the ass to put back together. It was a pretty old one though and luckily these newer ones don’t seem to be as complicated.

Now in this picture I’ve pointed out the wires that you’ll need to desolder. Yours might look a little different which is ok, just make sure you remember which wire goes where, because if you switch them around the wrong way it might not work. It would be a good idea to write it down where they go, or take a picture of it. While I was doing this I actually did forget where the wires went, but luckily since I was taking pictures I was able to put it back together the right way.

I’d recommend taking the whole PC Board out if you can, just in case you accidentally touch the soldering iron to the cassette shell, because it will melt.

Next take your soldering iron and just touch the little bulb of solder that the wire is connected to and pull the wire off. It should come right off without having to keep the iron there very long. Do this for each wire, and like I said before don’t forget where each wire went. You did write it down didn’t you?

Next you need to take your cord and wire strippers and strip off the insulation from wires so that it looks like the picture below. btw sorry for the crappy quality, I had taken a better picture of this but it was one of the pictures that was eaten by my computer.

Ok, now you want to solder the wires back to where they belong. All you have to do is just hold the wire down to the little solder bulb on the PC Board and use the soldering iron to just ‘tack’ it on. It shouldn’t take much and you don’t want to heat up the board with the iron too long or the traces on the PC Board could peel off.
Do this with each wire, making sure you are soldering them in the right place, remember what I said above about writing it down or taking a picture?

After you’re done with that, just put everything back together, and hopefully you didn’t lose any little pieces.

So there you have it, how to fix a car stereo cassette adapter. The only thing is that most people are probably switching to FM transmitters now. I got a couple of them, but I think they’re junk. I bought a cheap one at first, but even though it says it’s stereo it’s only mono. Plus it only transmits to a few stations and it’s pretty staticy. So then I went and got a Belkin one that transmits to any station, but it was worse than the first one as far as static and battery life. So then I found this guide on how to make the Belkin Tunecast II transmit better, which worked pretty good but then the screen got cracked somehow so I have no idea which channel it’s transmitting to anymore. So for those like me and still have cassette decks in their cars, but want to use their iPod (or other mp3 player) instead of listening to the radio, here’s my guide on how to fix your cassette adapter if it gets broken.