The Mercedes-Benz C32 AMG front turn signal uses 1156NA or 2357NA bulb sizes, while the rear turn signal requires 12496 or PY21W bulb sizes. The replacement chart covers 2002 to 2004 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156NA and 2357NA bulbs follow ANSI standards used in the United States and Canada, while the PY21W follows ECE standards used in Europe and worldwide markets. This distinction reflects regional regulatory differences in automotive lighting.
The 1156NA is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W. Its natural amber glass produces the required turn signal color without relying on a colored lens or housing.
The 2357NA is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with filaments drawing 26.9W and 8W respectively. The higher-wattage filament serves the brighter function, while the lower-wattage filament serves a secondary function such as running or parking light duty.
The BA15s base of the 1156NA and the BAY15d base of the 2357NA are not interchangeable. The BAY15d base has offset pins to prevent incorrect installation, whereas the BA15s base has aligned pins. Substituting one for the other is not physically possible without modification.
For the Mercedes-Benz C32 AMG, the front turn signal bulb size in 2003-2004 depends on the headlamp type fitted to the vehicle. Halogen capsule headlamp variants use the 1156NA, while HID headlamp variants use the 2357NA.
The 2002 model year front turn signal lists only the 1156NA with no headlamp variant distinction, indicating a single fitment for that year regardless of headlamp configuration.
The PY21W uses a BAU15s bayonet base, which has asymmetrically offset pins at a different angle than those of the BAY15d. This makes the PY21W non-interchangeable with either the 1156NA or the 2357NA despite sharing the same 12V, 21W electrical rating as the 1156NA.
The rear turn signal of the C32 AMG used the PY21W exclusively in the 2003 model year, while the 2002 and 2004 model years used the 12496. These two bulbs carry different base standards and are not interchangeable with each other.
The 12496 is a part number assigned by Philips and Osram rather than an ANSI or ECE classification, indicating it is a specialty halogen bulb specific to certain automotive applications and not part of a broadly standardized series.