Could be a fuse, could be a broken wire, could be a corroded terminal, could be the switch, or could be a knackered motor, and I guess there could be other issues!!!
Really Andy do a bit of the work and try and post up symptoms so we can actually provide constructive help........cant advise on fuse box as I have a D2, but have a look in the handbook and yes check the fuse for starters
In 95 yours will be a Discovery 1.......