Q: Left dipped headlight/main

Hi there. If you are lucky this is just a bad bulb. If the bulb filament failed, the module will notice turning this light on. Most of the time, though this is a failure in the ballast for the light it the adaptive motor if it is equipped with it. Typically the ballast will need to be replaced. I usually check the bulb first and replace it if the filament is bad. If not, then the ballast needs to be electrically tested to see if it failed. If so, then it will need to be replaced. If you are going to have this fixed, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the headlight and have this repaired properly.