1. The low beam headlights of Chevrolet Car do not light up
(2) Reasons for the failure: The dimmer is damaged, the circuit is open or short-circuited, the filament is burned out, and the lamp holder has poor contact.
(3) Fault diagnosis: Turn on the light switch, connect the "live" terminal and low beam terminal of the dimmer switch, and observe that the headlights are on, indicating that the dimmer switch is damaged; it still does not light up because the wire from the dimmer switch to the wiring harness is open circuit , or two low-beam lamp filaments of Chevrolet Car are burned out. You can check with the test light on the low-beam column of the left or right wiring board: if the test light is on, it means the low-beam filament of the Ford Car is burned out; if the test light is not on, it means there is an open circuit between the dimmer switch and the wiring harness.
2. Turn off small lights, tail lights, and instrument lights.
(1) Fault phenomenon: When the light switch is connected to the first position, the small lights, tail lights, and instrument lights are all turned off.
(2) Cause of failure: damaged light switch, open circuit, blown fuse, loose connector, broken filament.
(3) Trouble diagnosis: First check whether the fuser is damaged. If it is damaged, replace the fuse and turn on the gasoline light to check whether the fuse blows again. If it fuses again, there may be a short circuit fault in the line or switch, and the open circuit inspection method can be used to check. If normal, check whether the voltage on the corresponding terminal of the light switch is normal. If the voltage is abnormal, the corresponding gear of the gasoline light switch may be damaged. If the voltage is normal, check whether the corresponding bulb is damaged.