The Mercedes-Benz 190D uses a P21/5W bulb size for front side marker applications and 5008 or 232 bulb sizes for rear side marker positions. The replacement chart covers 1984 to 1989 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 190D front side marker position uses the P21/5W bulb across the 1984-1989 model years.
The P21/5W is an ECE-standard dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base.
The BAY15d base features offset pins that prevent incorrect insertion, a design characteristic that distinguishes it from single-filament bayonet bases.
The rear side marker position on the 190D uses two different bulb types depending on model year, with the 232 fitted to 1984-1985 models and the 5008 fitted to 1986-1989 models.
The 232 is an ANSI-standard festoon bulb rated at 12V and 3W, seated in an SV8.5 base, a cylindrical form factor held in place by contact pressure at each end rather than a bayonet or screw mechanism.
The 5008 is an ANSI-standard single-filament bulb with a BA15s bayonet base, operating at 12V and classified as a lower-wattage variant of the 1156 bulb family.
The BA15s base of the 5008 and the BAY15d base of the P21/5W share a 15mm collar width but are not interchangeable, as the offset pins of the BAY15d prevent it from seating in a BA15s socket.
The 232 festoon and the 5008 bayonet bulbs serve the same rear side marker position on the 190D but are physically incompatible with each other, reflecting a change in socket design between the 1985 and 1986 model years.
The P21/5W carries a dual-filament construction, though in a side marker application only one filament is typically active, meaning the secondary 5W filament may serve a combined parking or position light function depending on circuit wiring.