Interior Light doesnt work

The interior light doesnt work from the driver door only. I have found that the wire to the door switch is broken, but, I can't locate the wire. Does anyone know the route this wire takes so that I can find an end and renew it. I know it is purple and blue or possibly purple and white and it goes from the door switch to the multifunction unit, but I cant find any sign of it or the multifunction unit.
I hoping that this is also the reason that my headlight on warning is also not working. Thanks in anticipation.

Hi my wire broke a while back and it was a pain to find so i got a new piece of wire and poked it through the door switch side till it come out behind the fuse box and then rejoined it to the broken wire you will find the mfu by the fusebox and if you look up and around fusebox area at back you should find it the original wire is a pain to get back in as it goes round the right hand kick panel then up through the a pillar i hope this helps.

Thanks, your comments were invaluable, I've now found the mfu and traced the wire. In case anyone else is looking for it, it is purple and white, but, its encased in a protective black sleeve. I removed the fuse unit screws (2) and moved the fuse unit out of the way and then found the end of the wire and joined it to a new wire from the door switch. I managed to follow the original route. There is a hole that is about 3/4 inch above and 1 inch back from the door switch that goes directly through to under the dashboard.

While I was undoing the fuse unit I think I must have shorted something (stupid I know, but, I didnt disconnect the battery) problem is now the lights on indicator and low fuel indicator dont work. It may be coincidence, but somehow I dont think so, I'll let you know what happens!

Ever since i attempted to install aftermarket cd player my interior light stopped working properly... ...instead of coming "on" when doors are opened it "flashes" abour 5 times then stays off. after the engine is started and if the door is open it comes on, it even "dims off" when the door is closed. !!!!! i have checked the fuses for the door etc, but no luck. any suggestions would be appreciated. rang the tech guys at the only dealership in Auckland and they had never heard of such a thing in 20 odd years or land rover repair!!!! HELP!!!!

Good news is that the bulb was gone in the fuel gauge and it seems I must have imagined that there was a "lights on" warning light. All is now fine.