Last December I had a problem where none of the following were working: sidelights, taillights, lights on warning buzzer, instrument lights, back-lighting of fascia switches, rear fog light.
I studied the wiring diagrams in the Haynes manual and deduced that the source of the problem was the sidelight/dipped beam switch at the end of the left-hand steering column stalk. This was confirmed by unplugging the wiring connector from the left-hand multifunction switch and connecting the relevant wires together to bypass the switch - when this was done, all of the above features (which rely on the sidelight switch being on to work) worked as normal.
I purchased a brand new genuine Ford multifunction column switch, and all has been well until last night when the same symptoms as last time appeared. Now, have I just had bad luck with the new multifunction switch, or could there be a fault somewhere else which is causing the sidelight switch to fail prematurely?
FYI, my Fiesta is an LX built December 1996 and doesn't have headlamp levelling. Instead it has dim-dip, whereby relays switch the dipped beam bulbs on at a lower voltage when the sidelights are switched on. Previous to me replacing the multifunction switch in December the dim dipped headlights would always turn on simultaneously, but since then there has always been a visible delay between each light coming on, a bit like vacuum-operated pop-up headlights when vacuum is too weak to lift both simultaneously. Could a relay in the dim-dip circuit be on it's way out? I don't have much of a head for electrics so I'm kinda in the dark here (literally and metaphorically!) Any suggestions would be really appreciated.