hey guys

i'm helping fit a stereo to my mates car which is a b reg fiesta so has absolutely no stereo at all......

SO

we bought the CD player...JVC KG401 or something and i found these wires for it....



I know that red is my live....black is my ground.....brown is the tel mute (not needed)....yellow is my memory....

now what the hell is blue? any ideas??

Also there is a "line out" cable i believe (black cable coming from lower center of the headunit) Any ideas what this is?

And...

If i was to not connect the memory (yellow) would it not work? or would it just not save things like radio presets, equalizer settings, clock?

Where would I connect this to....the battery...but does it have to go direct from the cabin to the engine bay to the battery?

One more thing...

What rating in-line fuse would i need for the headunit live wire?

Help MUCH appreciated!!!!