Mercedes-Benz SL320 external light warning signal persists despite checking all bulbs on Mercedes-Benz SL320

Some Mercedes-Benz SL320 owners report experiencing persistent external light warning signals even after checking all bulbs. This issue may stem from slight corrosion on a bulb connection, which can alter resistance and trigger the warning unit. Additionally, owners have noted that a bulb may be nearing failure, with partial filament breaks or shorts causing high resistance and overheating. Some have also found that the internal hazard switch can remain illuminated in certain key positions, despite all indicators or hazard bulbs appearing to function correctly. For those facing this problem, it is advisable to seek a professional inspection at an authorized Mercedes-Benz service center, as ignoring these warning signals can lead to serious safety concerns.