First of all, please excuse me for my english, it's not my native.
Second, I know, I know, you can add AUX line-in to your radio using some kits. But they all require satellite radio installed, which is not an option for European cars. Anyway, may be someone could find it useful.
So here we go.
A little bit of theory.
As we know, CTS has an amp installed (located on the left of trunk). As I find out, volume controls affects not the radio itself, but controls amp directly. So all what we have to do is to replace sound line with our line-in, and we'll keep all volume controls works.
There are two channels on every mp3 player - left & right, each channel has 2 wires: signal (+) and ground (-). In most cases, both channels has shared ground wire. But, in our car there are two separate grounds (so we'll get less noise).
So everything we need to do is to switch 4 wires (+ -, 2 channels).
The best way to do this is use two relays.
Lets get started
What we need:
1. TR99-12VDC-SB-CD relays – 2 pc. (about $4 each) or similar.
2. Switch - 1 pc, ($1-2).
3. 3.5mm socket ($1-2).
4. Few colored wires.
5. Soldering iron and stuff
6. Piece of cardboard
7. Small plastic box (i've bought one in radio shop, together with relays, for $2).
Step 1. Preparing line-in socket.
Take any 4-wire cable and solder it to your socket. One wire to the left contats, one to the right, two wires to long one (that is common ground).
So now we have a 3.5mm cable
Step 2. Relay box
The best way is to make a circuit board, but I didn't have a tools so I just picked an air freshner made of cardboard.
Now make a holes for relays' contacts
I've put a little schematic on the back of the board so I didn't get confused. Both relays sit in holes.
Take a soldering iron and solder colored wires like this:
After soldering work is done, I put everything in this little box and marked wires.
Second, I know, I know, you can add AUX line-in to your radio using some kits. But they all require satellite radio installed, which is not an option for European cars. Anyway, may be someone could find it useful.
So here we go.
A little bit of theory.
As we know, CTS has an amp installed (located on the left of trunk). As I find out, volume controls affects not the radio itself, but controls amp directly. So all what we have to do is to replace sound line with our line-in, and we'll keep all volume controls works.
There are two channels on every mp3 player - left & right, each channel has 2 wires: signal (+) and ground (-). In most cases, both channels has shared ground wire. But, in our car there are two separate grounds (so we'll get less noise).
So everything we need to do is to switch 4 wires (+ -, 2 channels).
The best way to do this is use two relays.
Lets get started
What we need:
1. TR99-12VDC-SB-CD relays – 2 pc. (about $4 each) or similar.
2. Switch - 1 pc, ($1-2).
3. 3.5mm socket ($1-2).
4. Few colored wires.
5. Soldering iron and stuff
6. Piece of cardboard
7. Small plastic box (i've bought one in radio shop, together with relays, for $2).
Step 1. Preparing line-in socket.
Take any 4-wire cable and solder it to your socket. One wire to the left contats, one to the right, two wires to long one (that is common ground).
So now we have a 3.5mm cable
Step 2. Relay box
The best way is to make a circuit board, but I didn't have a tools so I just picked an air freshner made of cardboard.
Now make a holes for relays' contacts
I've put a little schematic on the back of the board so I didn't get confused. Both relays sit in holes.
Take a soldering iron and solder colored wires like this:
After soldering work is done, I put everything in this little box and marked wires.