"Dashboard lights flashing & relay clicking noise from engine fuse box area"
When does this occur?
Always?
Ignition ON?
Whilst attempting to crank the engine?
Have you checked the battery voltage? (e.g do the headlamps appear to be normally bright?)
have a look at this thread, this guy has had the same problems as you and it turned out to be a dodgy connection under the battery/engine fusebox, might be worth dropping him a pm to find out exactly where it was..
http://www.landyzone.co.uk/lz/1438165-post25.html
engin start relay?