Fitting Engine Start Accessory Button

As a first step, disconnect the battery to avoid any damage to the electrical system.
First, remove the plastic covers over the indicator stalk: the upper one is simply clipped in (just pull it to unclip it); the lower one, however, is secured with three Torx screws size 20 (two on top - one on the left and one on the right - and one located underneath, inside the designated access hole on the cover itself). Before unscrewing the screws of the lower cover, you must remove the plastic grip of the steering wheel position adjustment lever: the grip is secured with a 3 mm hex screw.
Once the covers are removed, locate the starter system connector, just behind the ignition lock.
Unclip the connector by pressing down on both retaining tabs simultaneously. The connector has 4 wires of different colours, which from left to right are: black (negative), red (switched positive), red (battery positive), red/black (starter motor). To install the accessory start button, first intercept the red/black wire of the starter motor and connect a suitably sized and length cable to it (ensuring proper insulation with tape), which will then need to be routed to where you intend to install the accessory button. It is suggested to place the button in the cigarette lighter position, to simplify both the cable routing and electrical connections (the button will need to be connected to a positive wire along with the starter motor wire). The cigarette lighter has two wires connected: one black (positive) and one brown (negative). The wiring diagram for the accessory start button is as follows: on the first terminal block (the green one), connect the red/black of the starter motor and the black (positive) from the cigarette lighter; on the second terminal block (the yellow one for the illumination bulb of the button), connect a positive and a negative.
Once the electrical connections are complete, refit the indicator stalk covers, the grip of the adjustment lever, and reconnect the battery.