First, the goal
    Through the understanding and detection of Passat car headlamp circuit, understand its working principle, master the detection method, can use the working principle to fault diagnosis and maintenance.
    Second, instruments and tools
    Passat car a high-impedance multimeter, a probe 4, a set of commonly used tools.
    Third, the content
    1. Passat car headlamp works
    2. Headlamp circuit detection
    (1) the ignition switch placed in the "ON" bit, and the light switch to the headlamps, headlamps near light should be lit, or use a multimeter or test light to detect its power circuit, light switch, grounding and filament The good or bad.
    ⑵ in the case of low beam light, press the headlamp light switch, high beam should be lit, or use a multimeter or test light to detect the power circuit in the light switch is good or bad, grounding and filament good Bad.
    ⑶ headlamp light switch detection: the light switch to the "headlamp" position, with a multimeter to detect its 1 terminal and 7,4 terminal between the conduction, the normal should be turned on (resistance is 0), otherwise the light switch is faulty.
    ⑷ detection of the headlamp light switch: do not press the variable light switch, with a multimeter to detect the connection between the 7,8 terminal, the normal should be turned on (resistance is 0); if normal, Press the variable light switch, check the 7,12 terminal between the conduction condition, the normal should be turned on (resistance is 0), otherwise the variable light switch failure.