Stereo Help JVC Fitting

[Scouser]

Hi,
I removed the standard stereo out of my T4 and fitted a nice new JVC with bluetooth, ipod ect ect.
Bought a ISo but the connection was too big for the back of the head unit even though it aid all lateset JVC,
So I got out the cutters and coppied all the connections.
The stereo works great but when I turn it off it doesnt hold memory for the stations, so I guess the permanent live isnt.
Anyone know which one

Thanks
Dave