The Mercedes-Benz ML320 parking light utilizes bulb sizes 12961, 1157NA, and 1034NA depending on the specific vehicle configuration. Data for the components covers the range from 1998 through 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz ML320 front parking light specifications reference three distinct bulb sizes across the model's production years: 12961, 1157NA, and 1034NA.
The 12961 is a Philips part number designation for a miniature wedge-type bulb in the T10 form factor, using a W2.1x9.5d base. It operates at 12V and draws 5W, placing it in the low-wattage category typical of parking and position lights.
The ML320 (2007-2009) uses the 12961 bulb for the front parking light, with the 2007 model year specifically noted as requiring halogen capsule headlamps for this fitment to apply.
The 1157NA follows the ANSI standard recognized in the United States and Canada. It is a dual-filament bulb with a BAY15d bayonet base and natural amber glass, rated at 12V with filaments drawing 21W and 5W respectively.
The dual-filament design of the 1157NA allows a single bulb to serve two lighting functions simultaneously, with the lower 5W filament typically assigned to the parking or position function and the higher 21W filament assigned to a stop or turn signal function.
The 1034NA shares the BAY15d bayonet base and natural amber glass construction of the 1157NA and is described as a variant of that bulb. Both carry the same 12V, 21W/5W ratings, though they are listed as separate part numbers within the ANSI standard.
The ML320 (1998-1999) and 2003 use the 1157NA, while the 2000-2002 model years use the 1034NA. Despite their close relationship, the two bulb types are not listed interchangeably within these specifications.
The natural amber glass designation in both the 1157NA and 1034NA indicates the color is produced by the glass envelope itself rather than by a coating or lens filter, which is a distinction relevant to regulatory compliance in certain markets.
The W2.1x9.5d base of the 12961 is a wedge-type fitting that requires no separate socket locking mechanism, as the base itself creates the electrical contact through tension within the housing.
The BAY15d base used by both the 1157NA and 1034NA features an offset double-contact bayonet design, where the two pins are positioned at different heights to prevent incorrect single-filament bulbs from being seated in a dual-filament socket.