Interior Light Issue - Wagon Help

Hey guys I'm having an issue with my interior lamp, my door switches and door ajar light all work fine and the fuse and globe are fine. I used a circuit tester to test the two cables that run to the actual switch/lamp assembly and one isn't receiving a current at all. The cable without the current is all black (it's not earth, as one of the mounting bolts acts as earth), it then feeds down and plugs into the same mounting board as the wiper control system and it's from there I don't know what colour it turns into as a bunch of little wires head behind the dash and over to the fuse box behind the drivers kick panel.

Is there common area this circuit fails or does anyone know if the wiring is different between wagons and sedans as the diagram I referred to appears to be quite different. Does anyone possibly even have a detailed diagram of the drivers kickboard fuse box and the relay sort of thing behind the passenger side where I loose the cables?

Any advice/help is appreciated, cheers!