my transit is dead?

My transit was working fine yesterday, i was playing about with the stereo wiring altho i dont think i actually done anything to it! and now today the van is dead no lights on the dash no attempting to start nothing just dead. i have a alarm fitted and this made a pathetic noise when i tried to trigger it off and wont work with the fob. The only thing that is working is the clock?? No lights were left on over night it just does not make sence. Also the battery was new in january so only 5 months old. Any ideas people? If anyone can help with my 6000 cd player too that woul be great.