The combination switch refers to the lever stalks located on the steering column behind the wheel. The left stalk typically controls the turn signals, headlight high/low beams, and parking lights, while the right stalk usually operates the windshield wipers and washer fluid. It is a complex mechanical and electrical assembly. Over time, the internal plastic detents can wear down, causing the turn signal lever to not “cancel” automatically after a turn, or the headlights to flicker when the stalk is wiggled.