when I fitted mine 2006 td4 auto it had the wires so did not take long the hardest part was cutting the hole out of the steering wheel and that was not to hard just made a paper template first. but when I came to work it ,it was different to a factory fitted one , first switch the switch on then press bottom button to switch the whole thing on and this will light up the light on the dash then press set , to switch it off just take foot of gas for a second and flip bottom button and the light on the dash will go out , but it will not switch on again until you have switched the main switch off then back on , I do not know if this is the same for every after fit but this is how mine works but once you know it is no problem.