Interior lights not working

My car has an interior light issue, this includes the red door lights, the instrument cluster and radio lights all are working as should.

The interior lights, none of them will switch on, what ever I try.

Everything else works as should, although, the passenger door lock will not unlock or lock the car when using the key in the lock to open.

The key fits the lock, go's round, well, left and right, so i'm convinced it is the right key to this lock.

Is this a common issue? 

I have checked the fuses, nr 15 it was, was 100%.

Are these symptoms, interior lights and passenger door lock, related to each other?