Lighting circuit problrm

Hi, My friend has 93 k reg disco TDi but no internet. All side lights and head lights out after faulty trailer board plugged in and now removed. No fuses in the panel under the steering wheel are gone and bulbs seem ok. Checked wiring diagram, there is a fuseable link shown before the switch but for post 93 models, I think these are in the ones with the fuses under the bonnet. I cant see why fuses havent blown, is there something I am missin? Any help or suggestions would be greatly appreciated please. Thanks