Symptom: a Santana century rookie car in the use of headlights, the audio will disappear, must be re-proof, serious, and even lead to sound can not work.
    Troubleshooting: first remove the fuse box, check the audio fuse, there is no fuse and poor contact with the phenomenon, then remove the audio host, check the rear of the power plug, also plug the same good. Taking into account the use of headlights when not in use, and the use of normal sound, and open the headlamps, the sound abnormalities, therefore, is suspected because of line pressure caused.
    From the battery directly pull a power cord to the audio power supply, and then open the headlamps, the sound is normal, the fault disappears. To determine the car has a power contact contact loose or there is an open circuit, resulting in line pressure. Follow this idea, carefully check the engine peripheral circuit, starting from the battery stigma, until the alternator armature line, in addition to the total power fuse, are in good contact, but open the fuse cover a look, the fuse holder has been Burned deformation, and melting pieces are also melting deformation, resulting in poor contact, so that the line is in a non-pass state. In the use of high-power electrical appliances (such as headlamps), will inevitably lead to line pressure, so that some low-power appliances power.
    So what is the cause of the fuse burned it? The original car factory, the fuse installed with a deviation, not inserted in the middle of the socket, the contact is not good, and in the large amount of electricity, resulting in frequent flashover, Device. Find the point of failure, re-change a fuse assembly, and rewrite the harness to ensure good contact, open the headlamp and then test, the sound can be used normally.