What is the reason when the high beam doesn't work but the low beam is normal?

[Lucille]

Reasons for high beam failure: 1. When turning on the headlight switch, neither high nor low beams work: Check if any fuse in the fuse box is blown, and whether there's a fault between the car light switch and the dimmer switch. 2. The live wire of the dimmer switch is connected to both high and low beam terminals: If all lights work, it indicates a fault in the dimmer switch. If only the high beam works when connected while the low beam doesn't, the fault lies between the dimmer switch and the headlight or between the dimmer switch and the low beam. 3. The high beam doesn't work: Check if the high beam indicator light is on. If it is, the fault is between the terminal board and the headlight. If not, the fault is between the terminal board and the dimmer switch. Related information: If the bulb burns out immediately when turning on the light switch, check for any short circuit in the charging circuit. If bulbs frequently burn out, check whether the voltage of the generator voltage regulator is set too high.