The Mercedes-Benz 380SL front side marker bulb uses a P21/5W size, while rear side marker bulbs utilize 232 and 5008 sizes. The replacement chart covers 1981 to 1985 model 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 380SL front side marker position uses the P21/5W bulb across all model years from 1981-1985.
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 to prevent incorrect installation orientation.
Despite being a dual-filament type, the P21/5W is classified in these specifications as a signalling bulb rather than a combined stop/tail unit in this application.
The rear side marker position of the 380SL uses the 5008 bulb for model years 1981-1984.
The 5008 is an ANSI-standard single-filament bulb operating at 12V with a BA15s bayonet base. It is a lower-wattage variant of the 1156 bulb family, and the two are not interchangeable despite sharing the same base type, due to the wattage difference.
The 1985 380SL rear side marker departs from the 5008 specification, using instead the 232 bulb.
The 232 is an ANSI-standard festoon bulb rated at 12V and 3W, fitted with an SV8.5 base. Festoon bulbs are cylindrical in form and seat by contact pressure at each end rather than by a bayonet or screw mount.
The front P21/5W and the rear 5008 are not interchangeable. The P21/5W uses a BAY15d dual-contact base, while the 5008 uses a BA15s single-contact base, and their wattage ratings differ substantially.
The P21/5W follows ECE regulations, while both the 232 and 5008 follow ANSI standards, reflecting a split between European and North American specification conventions within the same vehicle's lighting system.
The 232 festoon and the 5008 bayonet bulbs used in the rear side marker position are physically and electrically incompatible with each other due to their differing base types and mounting methods.