Phono sockets in-car

[Centurion07]

I know this is probably a silly question but we've just bought a '57 plate 207cc and want to connect an mp3 player to the stereo.

Searching the net I can only find reference to the 207 having 2 phono sockets whereas ours has 3. It has factory fitted sat-nav with a 6/7 inch screen if that makes a difference to the following:

In the glovebox is a small box with 3 phono sockets on it, red, white and yellow. I bought a 3.5mm stereo to 2 x phono plug lead thinking it would be the right one as I only need left and right audio. However, as pressing the source button on the car stereo won't switch it to aux, I'm assuming it can't "see" the mp3 player so was wondering do I actually need that third phono plug to be connected for it all to work or is it likely to be some other electrical gremlin?

[sinizter]

Yellow sounds like video.

Did this sat nav have a TV/DVD function or something like that ?

[Centurion07]

That's what I'm thinking too. Still waiting for a manual from Ebay to check these things as dealer didn't have one. It seems like the sat-nav can be switched to dvd mode though but I didn't think the lack of a video plug would affect the L+R audio channels if I'm just using an mp3 player?

[sinizter]

Centurion07 said:

That's what I'm thinking too. Still waiting for a manual from Ebay to check these things as dealer didn't have one. It seems like the sat-nav can be switched to dvd mode though but I didn't think the lack of a video plug would affect the L+R audio channels if I'm just using an mp3 player?

Then it probably needs to be in DVD mode rather than Audio Aux in

[Centurion07]

Fairly sure I tried that. I remember pushing just about every button I could see and trying everything I could think of but I'll give it a go when she gets back home. Cheers.