Fault phenomenon: when a Santana new car is using a headlight, it will make the sound memory disappear and must be rechecked. When it is serious, it can even cause the sound to not work. Maintenance: first take off the fuse box, check the sound fuse, there is no fuse and bad contact phenomenon, and then take down the audio host, check the power plug in the rear, and also have a good connection. Considering that the sound is used normally when the headlights are not used, and when the front light is opened, the sound is abnormal. Therefore, the suspicion is caused by the line depressurization. Directly pull a power cord from the battery to the audio power supply, then turn on the headlight. The sound is used normally and the fault will disappear. So as to ensure that there is a power supply contact point loose or open circuit on the vehicle, causing the circuit to reduce the voltage. Following this idea, check the peripheral circuit of the engine carefully, starting from the battery column head to the AC generator armature line, in addition to the power total fuse, all the contact is good, but when the fuse is opened, the fuse seat has been burned and the fuse is melted and deformed, resulting in the bad contact and the line. The road is in a state that seems to be through. In the use of high-power electrical appliances (such as headlamps), it will inevitably cause the circuit to reduce voltage, so that some small power appliances will be cut off. What is the cause that causes the fuse to burn out? When the car is out of the factory, there is a deviation in the installation of the fuse piece, not in the middle of the socket, and the contact is not good, but when the electricity is large, it causes frequent jumping fire and burning the fuse. Find a point, re replace a fuse assembly, and re weld the wiring harness, ensure good contact, turn on the headlamp and then test the car, the sound can be used normally.