If it's the standard D8 pug head unit and boot-mounted cd changer, there's only two connections - one on the changer and one at the back of the head unit. Could well however be that the cable has been crushed/cut somewhere in the middle, which'll be pretty much impossible to spot without ripping the whole thing out...
<steve_earwig> I think this forum is more about keeping our cars going with minimal outlay than giving our cars more reason to go bang
Bumpy West Yorkshire roads mean it cuts in and out alot. All okay stationary or on a decent piece of road.
The car is a D9 HDI 90 estate so yes boot mounted CD player. I thought the head may be jumping as the cd player looks real cheap, it could be both but not easy to tell.