The head lights on my Merc A190 has suddenly started to malfunction. The high beam stays on whether the lever is in the up or down position, causing violent reaction from oncoming drivers.I was called all kind of names over the last few days. Even when the light switch is in the off position and the lever is in the high beam position, the lights stay on. When the switch is in the off position and the lever in the dim position, then the lights are off. Can someone please explain to me what has gone wrong and how to fix it.