just to make it clear for you
the 3 wires on the rear of the switches locate here

brown to brown on next switch
grey/green to grey green on next switch
black/red to the blue multi plug in the pass side footwell
if you look at the image below you can see the black/red wire locates in-between the brown/whit and the blue/red
or if its easier the 3rd slot from the right
