Inconsistant window operation

Hi. Golf mkiv 1.6 1998/99 AKL engine. Windows have become inconsistant. They may operate normally, move an inch at a time, or not at all. Doesn't matter which window switch you use. One rear door completely dead. Cant open it and no window or lock operation but that's always been like that. Seems radio is affected too so I'm thinking an earth but can't find one that makes any difference. Can anyone help shed some light on this please?

thanks

Check the wires in the door shut conduit tubes, all of them.

will do, thanks