This afternoon I replaced some dash bulbs.
I changed the bulb in the headlight switch which had blown.
I tested afterwards and all worked well.
Next was the heater panel bulb, I swapped this over and then put the dash back together.
But this time when I turned the ignition on I now have no dash illumination at all!!
All the switches and the speedo/dials are in darkness.
I checked fuse 21 - dash lights and this was fine.
Any other ideas?