You ask for wiring details, but give no info ....
on the radio system. There should be a model identification in the Cassette door, or in the radio manuals, or in the card with the security code. May be posting pictures of head unit, CD changer and amplifier would help.
Javier
Think you should get a multimeter ...
A Multi-Meter is a handy tool for any electrical checks, not only at the car, but also at home, I think you need it, if you want to carry out this diagnose, as I told you, it is not only to check for not blown fuses that I'm sure you do not have, but for tricky things, the things that make an intermittent fault, poor connections, broken fuse links, and so. There are different prices depending on brand and functions, mine have AC/DC voltage and Amps, Resistance with continuity bell (Ohms), Capacitance, Frequency, and also some Diode and Transistor test functions. I paid about 110 USD about 12 years ago. I think it was a cheap one as the brand is not top (Beckman). You may probably find something better at a lesser price this days (Technology is a b..). Radio Shack is a possibility, check the web though, or get recommendations from someone from the forum living in USA.
If no meter at all, and you have a portable stereo system with a "Line In" RCA input and output to speakers, you may get creative and do some sound testing, but if no sound, you will not be able to check the presence of supply voltage at the amplifier, and, for example, at both terminals of every fuse.
The headphones will let you listen for signal at desired points, just use some extra bare wires to connect, 32 ohms is low impedance but you should hear something with them. At least it will let you discard problems in the head unit.
As for the speakers, you should have 2 components (H/L) below each screen at the rear side.
Javier