Stu , i'm no expert , but as far as i'm concerned your high beam dimmer has dik all to do with your dash lights.. only the high beam indicator. If your can confirm that the dash light fuse is ok (and you have 12v there) and that you have the dash light dimmer on its highest point (just before dome light comes on) , i'm saying its the plug where it plugs into your printed circuit board . I bet if you move it around or jiggle it a little, light should work.......providing that all your dash light bulbs never blew .