Why is one side of the Mercedes headlight on?

[DeJude]

Mercedes headlight on one side is caused by the turn signal switch not returning to its original position. Reasons for not returning: The "interference" between the return lever and the return disk is the key to the automatic return of the turn signal. That is to say, when the protrusions on the surface of the return lever or the return disk are severely worn, the return lever and the return disk cannot "interfere" with each other. As a result, the turn signal cannot automatically return to its original position when the steering wheel is straightened after the vehicle completes a turn. Solution: To solve this problem, it is necessary to remove the steering wheel and combination switch, check the wear degree of the return device, and selectively replace it according to the specific situation. Of course, besides malfunctions, sometimes the turn signal really cannot return automatically.