Mercedes-Benz ML430 front fog light bulbs use H3 size while rear fog light bulbs use P21/4W size. The replacement chart covers 1999 to 2001 production 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 Mercedes-Benz ML430 uses the H3 bulb for front fog lights across the 1999-2001 model years.
The H3 is a single-filament halogen bulb operating at 12V and 55W, mounted on a PK22s base.
The H3 is an ECE-standard bulb with approval for use in Europe, worldwide markets, the United States, and Japan.
The rear fog lights on the ML430 use the P21/4W bulb across the 1999-2001 model years.
The P21/4W is a dual-filament signalling bulb rated at 12V, with a 21W primary filament and a 4W secondary filament.
The P21/4W uses a BAZ15d bayonet base, which is an offset-pin design that prevents incorrect installation by ensuring the bulb seats in only one orientation.
The P21/4W is an ECE-standard bulb, indicating it conforms to European and international regulations for rear fog light signalling applications.
The H3 and P21/4W are not interchangeable, as they differ in base type, filament count, wattage, and intended function.