I have a broken snap connector in my Series 2. It is a brown wire (with blue line) under the shift console. Aren't brown wires usually earth (ground) wires? All switches work still, just this connector has snapped off.

 

I looked at my Series 3 wiring diagrams, and brown wires are all power wires. The brown/blue wires showed up as power door lock wires on XJ6 and power window switch power wires on XJS.

Not sure on your car, but maybe someone bypassed that broken wire in the past and that is why everything still works.

Best thing would be to get the wiring diagrams for the car, check ebay or parts suppliers.

 

That explains why my the door lock switch doesn't work. Thanks so much for helping me out. Now i just need to figure out which 2 of the 6 prongs on the switch the 2 wires go to. The series 2 cars have multiple wires to each switch.....argh.