Electrical Fault - Dashboard

Ok, so my disco has a few electrical problems.

battery went flat as a result...

front wipers went off intermitting - they work but intermitting doesnt.
interior lights not working when door is in use (open - not dimming)
heated rear screen and wiper are not working.

on the dash console, the light for the heated rear screen is not coming on, so this could mean that there is a problem at the frontend.

if anything can be suggested as to why these arnt working.

Many Thanks

faulty earth or a blown fuse!