Audi a4 b6 2003 tdi lights flicker on and off the dash and others like
 

hi I'm having trouble with my a4 b6 one day last week I got in it and I started it and put lights on and I realised the dash lights were going on and off and the horn, indicators, main beam and wipers stopped working too but sometimes when driving it starts working properly. can anyone give me some advice where to check or if this has happened to anyone else before?