In preparation for MOT checked all the lights and found that the fog light on my 4/4 sport wasn't working. It's a light I have never had to use. Checked the fuse - OK. Power to the fuse - OK. Had a look at one of the brake lights which , besides the earth lead, had two live wires; one I assume is for the brake lights in the dark and the other live when brakes are applied. Having no wiring diagram I am lost what to do next. Any suggestions welcome
