My interior lights do not work on automatic (when the doors are opened). They work when switching the overide on the lamp itself, so power is there. All the other auto lamps work Ok, ( the footwell,puddle, vanity mirrors and glove box). It all seems to point to the FET courtesy dimmer in the Central Junction Box. Has anybody any ideas?

Sometimes the obvious is over looked, the switch on the interior light is a three position switch, Permanantly On, On With Opening and Permanantly Off. Apologies if you knew that

Glove box is a separate circuit, the same with vanity lamps.
Also the exterior puddle lamps.
But the footwells, interior front and rear and loadspace lamps are all on the same FET.
So, if the footwells work and the interiors don't, there is only a matter of either bad circuit or they are manually switched off, like ad210358 said.