On my 88 (Tor***) Urq, when I press the 'diff button', its yellow triangle lights up, but the diff lock diagram does not, nor does the ABS Auf light come on. (It does when I press the ABS Auf button). Any clues where to start? And by the way, heated driver seat, the switch lights up, but the seat does not get hot, or do they take a long time? Remember, English summers are cool! TIA