I owe a Citroen Berlingo 2002, problem is no audio in.
The result is a 3.5mm female jack getting out the radio. So when you want to listen to music, set the volume of the radio down to minimum, connect your mp3 player (phone, ipod, etc.) and click play!
We need to remove and disassemble the radio and make 4 little weldings in it. We will use an audio 3.5mm female jack cable (but you can use whatever sound interface you like - es. male 3,5mm jack, female-male 6,3mm jack, female/male RCA audio - )
The VDO RD3-00 is a car radio sold with other cars by Citroen/Peugeot:
Citroen Xara Picasso
I did get the info for the welding from this article, but didn't understood anything else because it is written in Spanish, I think!
Step 1: Remove the Radio
To remove the player from the fascia, just insert four small screwdrivers or something similar into the slots at the sides. This is from a tutorial from the web, I actually took it off by forcing it with a cutter... your choice!
Disconnect the ISO connectors (Black for power and VAN bus data communication; White for the four speakers - see piture) Disconnect the grey cable on the right, too.
Step 2: Open the Radio
Force the top iron cover with a screwdriver
Step 3: Remove the CD Reader
Unscrew the four screws shown in the red boxes in order to remove the CD player. Be careful to the jack panel underneath!
Step 4: Make Welds
Cut the audio wire (connected to the jack or whatever interface you chose). There will be two smaller wires (left and right) and some very thin raw copper wires (ground)
We weld the left wire to FLV and RLV (see picture).
We weld the right wire to FRV and RRV(see picture).
We connect the ground to the side of the copper box.
FLV: front left voltage
FRV: front right voltage
RLV: rear left voltage
RRV: rear right voltage
Step 5: Reassemble the Radio
I made the audio wire pass throw 2 of the 4 holes used to remove the radio (making them unusable was not a problem for me, since i removed the radio with a cutter).
Reconnect and reassemble everything back.
When you are listening to the radio, set the volume down to minimum and connect an audio device to the jack. You should now be able to listen to the sound emitted by the device. You will set the volume only through the device. If you set the volume of the radio up the sound of the radio will overlap the sound of your device.