To install the 12V battery on a Vespa 125 without the glove compartment, the battery must be fitted in the space under the seat on a bracket, connecting the + and -. Connect the positive terminal of the battery to the junction box. For the wires below, connect the black wire, which is the battery ground, disconnect the green wire, and attach the positive from the battery to it. The green wire that was connected above should be left disconnected. This means that the current produced by the Vespa will be lost. Essentially, keep the Vespa connected to a battery charger. The YouTuber also modified the rear light stop by purchasing a normally open switch, meaning that when you press it, it makes contact and lights up. This works by installing a new bulb in the rear lamp, which will serve as the stop light (which is absent), and two wires: one goes directly to the battery (+) and the other connects to the positive of the LED light. However, you need to modify the horn switch, which is the button located on the right handlebar: unscrew the central screw and pull it out. We are only interested in the green, white, and black wires. Then, modify the horn as it currently interferes with the battery. Install it backwards so that it only touches when pressed. Now, for the wires: the green goes where the black was, the black goes where the green was, and the white should be placed as shown in the photo, behind the horn. Then, remove a small piece of metal next to the horn (as shown in the photo) to prevent the battery from shorting out.