For about five dollars in parts, the CD changer’s cable on a 2004 Discovery can be converted into an aux input, allowing you to connect any audio device to the stereo. A little more cash and you could have both, but I opted to sell the CD changer instead and use the funds to buy a new phone that can carry my entire music library. I still have the factory in-dash CD available for the occasional “guest” disc I might want to play. The in-dash was originally designed for the nav system’s data CD, but I find I much prefer the Google Maps / Phone GPS combination for the few times I actually use such things.
The parts you need for your install may vary depending on what you want to accomplish. As I had a fairly generic setup in mind and did not want to retain the factory changer my shopping list consisted of: black heat shrink tubing, audio-grade silver solder, gold-plated RCA jacks, and the smallest black plastic project box I could find (which was still too big). I could not find a project box I liked anywhere, so the local Radio Shack got my business on that one. The rest of the materials were ordered from Parts Express along with a 12V cigarette lighter soldering iron that is quite possibly the best soldering iron I have ever used (I will be ordering more of them).
When you are pulling the wiring out from under the seat bracket, watch out for the unprotected wiring that heads to the seat heater. You will want to carefully pull the CD changer wire bundle up from under these wires, and then tuck them back down safely in the carpet. Also, if you are not confident about slicing into the shrink tubing surrounding the audio wires now would be a good time to shut off the permanent power feed that runs down them. This can be done by pulling fuse #17 from the fuse panel under the steering wheel, which is a blue 15A fuse. Note that you will loose the settings in your stereo and have to enter the security code again. If you do not have the code call your Land Rover dealership and get it, you will want it on hand anyhow in case your battery ever dies or you ever blow a (stereo related) fuse.
I used the description provided here to decipher what each wire is used for: Audio Wires. In a nutshell, the wiring configuration goes like this:
- White – right channel, positive
- Black – right channel, negative
- Red – left channel, positive
- Gray – left channel, negative
All other wires can be sealed off and ignored, however the purple wire was an “always on” primary 12V power feed to the CD changer. Considering the amount of power a six-disc CD changer requires, this wire could easily be re-used to power small devices (such as charging your MP3 player). Note that on the 2004 Discovery, a change was made to the wiring such that grounding out the green wire will NOT leave the audio channel open. At first I feared this might doom me to buying the $120 BlitzSafe box (which is made specifically to address the 2004 change), but as it turns out those of us with the factory hi-line Nav system have a much simpler (and nearly free) solution available to us.
When you are done either duplicating what I’ve detailed in the pictures below (or setting up your own system to your satisfaction) it’s time to “reprogram” your stereo for auxiliary input mode. This is a painfully time consuming process of pressing a whopping 4 buttons (5 on some vehicles). With the stereo on and in any mode, press and hold the Tone button for a little over two seconds until the super-secret hidden cool-stuff menu comes up. On that menu, locate and press the soft-key labeled “Aux” until the screen displays “AUX Mode on” in great big letters. Now you can hit the Tone button again or just wait for the menu to time out. When you are back out of the menu again go in to CD mode (if you are not there already). In place of where the CD Changer soft-key once was, you will now have a soft-key labeled AUX—press it.
Now it is time to test out your new setup. Make sure the volume on your stereo is turned down low to be safe, hit play on your device, and see what happens. Note that on most devices you will need to turn the device volume all the way up to reach what is known as “line level” before you will get a good amount of sound and a familiar response from the stereo’s volume controls.