Shortly after a year of ownership on this A6 Avant, the fog lights stopped working. I recently did some work on the front end and also replaced the headlight switch hoping that the Front Fog lights would work again (last year I replaced the bulbs as well; the wiring looks intact; even tried a different fog light assembly); still the front fog lights do not turn on (even when the headlights are on). Is there a relay that controls the on/off function for these lights?