Audi a3 indicator wiring needs to find the taillight cable first. According to the public information, it is known that the tail light line needs to be found first in the wiring of the indicator light, and the tail light line is generally located in the trunk protection board. Because there are many control lines of car lights, it is impossible to distinguish them by color, so it is necessary to use an electric pen to detect them. Because some cars don't have fog lights, you just need to find the control lines of running lights and brake lights, and finally disconnect the lines. Sign lights are generally bought with fixed brackets, which are screwed against the rear bumper and then tightened. Because of poor waterproof performance, the adhesive tape or glue is often corroded by rain after installation, which may cause the indicator light to fall off. If there is no fixed bracket, only the rear bumper can be punched, which is troublesome and harmful to the vehicle.