Technician A says that headlamps assemblies have UP and DOWN adjustment. Technician B says that headlamps assemblies may have LEFT and RIGHT adjustment. Who is right?

• A. Only A
• B. Only B
• C. Both A and B
• D. Neither

Answer: (C)

Headlamp aiming is two-dimensional. To illuminate the road properly and avoid blinding other drivers, the beam must be adjusted both vertically and horizontally. The vertical adjustment moves the beam up or down, setting the height of the light on the road. The horizontal adjustment shifts the beam left or right, lining it up with the vehicle’s centerline and lane position. Many headlamp assemblies include both kinds of adjustment, using manual screws or sliders, or sometimes electronic actuators in more modern systems. Because both directions of adjustment exist in typical headlamp designs, both statements are valid.