Symptom: A Passat B4 sedan equipped with a 4-cylinder AEP engine. The car used in the process of the emergence of such symptoms: when the small light switch to open, the small lights are not bright, and the headlamps are lit light, and this time the dashboard light indicator light is always bright, but the instrument lights But not bright, and then carefully observed, found that the generator charging indicator light in the open switch, it can not be normal light.
    Troubleshooting: turn on the ignition switch, so that the magnetic field on the generator line, but the dashboard on the charge indicator is still not bright. Check the maintenance data, with a multimeter to measure the generator magnetic field line to the instrument socket 13 # pin between the line resistance of 1Ω or less. As the car's generators work properly, the initial determination of the dashboard line problems. Continue to check the lighting system, when the headlamp switch to open the light position, the instrument panel on the high light indicator light. For this failure, first check the headlamp switch, headlamp switch pin marked as:
    5858RXzXr56D5658b
    TFL58LNLNSL30SRA31 empty
    Corresponding wiring harness socket: 56D, TFL and SRA were vacant. Check the headlamp switch alone, check the results are as follows:
    When the switch is off: TFL-Xz-56D is connected. When opening a small light: Xz-56D, 30-58L-58-58R connected. When the headlights are turned on: Xz-56, SRA-30-58L-58-58R are connected.
    The above conditions meet the normal working conditions, to prove that the headlamp switch no problem. Then check the headlight switch harness and headlamp switch pin connection, but also check the 30 # pin to the dashboard wiring harness 12 # pin connection lines are normal. Thus, the problem went to the dashboard harness, it seems not disintegrate the dashboard is to solve the problem. So that the instrument panel disintegration, careful observation of the instrument panel line welding situation, found in the harness socket 28 pins, nine pins of the welding has been welding, these solder joints include charging lights and small lights Pin. The welding of these solder joints to re-welding, the car back to normal.