The digital display on my climate control has been cutting on and off but my ac, climate and fans all still worked. Now i got a 2nd hand replacement unit, fitted it and the display all lights up great but now when i press the air con button my air con doesnt come on. So i refitted the original and the air con came on again then refitted the replacement and again it all lights up great but no air con? My A4 is a 1996 model and as far as i know the replacement is from a 1998 model, would this make a difference or is it a case of the 2nd hand replacement is also faulty? The newer unit did look slightly different but it pluged in and fitted fine and as i said it all lights up great. Any suggestions on how i can get my air con to work with the new unit would be greatly appreciated as now with all the faffing about my original unit wont display at all now and it wont let me turn the fan speed up or down!!! Thanks chaps.