Thanks very much Steve, could always give them a call but I guess it could be difficult for them to estimate the cost. Have read a bit about using an obd2 adapted but just wasn't sure if it would be able tell me what I need to know, unless it finds an error code but I really don't know much about using that software and kit.
Thanks very much Colin, I've still to do that. I would love it to be that but I have a feeling that it not going be a fuse as looking at the fuse diagram the fuse that does the sat nav, audio also does he overhead controls which I assume are the interior lights, etc and they're working fine. Will defo check though. Could be lucky.
Just a shame as from searching on the web it seems pretty rare and the CTs tend to be really reliable. Just my luck to get something like this. May need to take up singing lessons to improve my attempts at passing the time on my daily commutes