My crappy sony deck stopped
playing CDs, so I bought an 05 WRX 6-disc cd changer.
All 93+ Subarus use the same harness/plug. Except for SVXs, and 93-94 Legacies. So this isn't a plug and play type deal and you'll need to make a harness.
To do this you need a Legacy harness and a reverse harness for a newer Subaru. I used the harness that was hooked up to my old deck and bought a reverse harness from David Carter for $17 shipped. I highly recommend you buy one from him because it has the extra illumination wire and he's very helpful if you have any problems.
So I guess the first step is to take out the old stereo and harness. When you take out the cup holder you'll see these two screws. Undo them. And also take out the ashtray. There are two more screws holding the trim piece and the ashtray rail in place so you'll need an offset screwdriver or something to get them.
Then undo the 6 screws holding the din rails in place:
There are two more farther in that Best Buy convieniently forgot to replace when they installed my old stereo.
Then you'll end up with something like this after you take the old harness off. You can see how best buy really does top notch work what with the crimp on connections and all.
Cut that apart or buy a new harness and you'll have something like this.
Now you need to put it together. I went to Radio Shack and spend about $40 on a soldering iron and soldering iron accessories. They had a nice little kit for $20 and then I bought more solder, tip tinner and cleaner, heat shrink tubing, and some zip ties.
What I should have done is spent that money on a photography book because apparantly I suck. Actually my screen is broken so I have to let the camera take it's best guess.
If you want the dimmer to work, you'll have to modify the legacy harness. Vikash recommended moving the ground wire to illumination (+) awhile back and then directly grounding the wire on the reverse harness to the stereo body. So that's what I did. If you don't have a power antenna you could also use that wire (which I realized after I'd already started soldering).
Note: I do not recommend grounding to the stereo body. Ground it to the body of the car or the negative terminal if you want to run all that wire. My changer cuts out occasionally and I intend to re-do things.
the black wire is the one I moved. I jammed a small scredriver in there and it popped out. There's a little tab on the terminal that rests on another tab in the plug. After I bent it back down it snapped into the new position.
All my wires were labelled correctly, but you may want to take a look at some pinouts just in case. Here is a Legacy pinout that Vikash made, and here is a WRX pinout that David made. This nasioc thread also has useful Subaru stereo information (and guess who posted it).
To solder you'll want to twist the wires together like this:
Then use a clean soldering iron to heat up the wires. Don't forget to slide the little shrink wrap tubes over the wires beforehand. Then solder. There are plently of guides how to do that online like this. The important part is to keep the iron clean and to use what you're soldering to melt the solder and not the iron itself. I found I had to help the solder melt though because the wires weren't staying hot enough.
Don't use too much.
Then after awhile you'll have something like this:
Use a lighter on the heat shrink, throw on a zip-tie or two or some fancy cable wrap to keep things organized, and you should end up with a pretty nice looking harness:
Put the new CD player in the DIN rails, connect the harness, and take it to your car:
Plug it in:
Screw everthing back together, put on the trim, and you're done:
I found that my front speakers weren't working, so I pulled everything out and re-checked the harness. No problems there so it must be a speaker problem of some sort. Fade and balance work right for the rear.