all dash lights gone

all my dash lights have suddenly stopped working, the clocks and all the lights on them work its just the illumination thats off.

 where should i start? is there a fuse for these, mines all writen in german on the fuse box.

check the sidelights on the front or the back and see if you have one side out, if you have u got a fuse gone on most cars the dash lights are powered from one set of sidelights( left or right) if your sidelights are all ok check the plug on the back of the clocks, could have just poped out a bit!

side lights are good.
  
 ive checked the light switch, wires seem ok. which one would be the culprit??

 ive got a slight leak from the front screen and its damp around the fusebox, im hoping that isnt anything to do with it?

What did you do before the dsh lights went off?
Is the main dimmer on the light switch working?

the only thing i did was swap the use for the rear number plate lights. maybe i upset something there? not sure which fuse runs te dash lights, can anyone help with that, its an 83 gti.
 thanks

From what I can remember the dimmer light wire is blue/white, I would of thought that fault is behind the clocks. Its not unknown for all the dash bulbs to blow at once. I would take out the clocks and check the bulbs, while you at it you can change them over to 2w to make them brighter.

Try bridging the blue/white onto the green/white then as soon as the light switch is put on full power will go to the interior lights eliminating a fault with the rheeeostat, who needs a dimmer anyway!
Nick

Rheostat on the headlight switch probably died.  This would kill the dash lights - and might as well hardwire to the main switch power (bypass the dimmer as previously suggested).