The Mercedes-Benz 500SEL front side marker bulb uses a 1034 or P21/5W size, while the rear side marker bulb requires a P21/4W or 3893 size. The replacement chart covers 1984 to 1993 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 500SEL uses two distinct bulb standards across its model years: the ANSI standard, which applies to US and Canadian markets, and the ECE standard, which applies to European and worldwide markets.
The 1034 bulb, used in the front side marker position for the 1992-1993 500SEL, is an ANSI-standard dual-filament bulb rated at 12V with a 21/5W output and a BAY15d bayonet base. It is a variant of the widely used 1157 bulb.
The P21/5W bulb, used in the front side marker position for the 1984-1985 500SEL, is an ECE-standard dual-filament signalling bulb rated at 12V with a 21W/5W output. It also uses a BAY15d bayonet base.
Although the 1034 and P21/5W share the same BAY15d bayonet base type and operate at the same voltage and wattage, they are governed by different regional standards and are not confirmed as interchangeable within these specifications.
The rear side marker position for the 1992-1993 500SEL uses the P21/4W bulb, an ECE-standard dual-filament signalling bulb rated at 12V with a 21W/4W output. Its base type is BAZ15d, which is offset and distinct from the BAY15d base used in other bulbs listed here.
The BAZ15d base of the P21/4W is physically incompatible with BAY15d sockets. The offset pin arrangement of the BAZ15d prevents installation in a BAY15d housing, making the rear side marker socket for 1992-1993 non-interchangeable with the front side marker socket.
The 3893 bulb, used in the rear side marker position for the 1984-1985 500SEL, is an ANSI-standard dual-filament bulb with a BAY15d bayonet base, rated at 12V and designated for specialty applications.
The 3893 and P21/4W serve the same rear side marker position across different model year groups, yet they use different base types, BAY15d and BAZ15d respectively, making them physically non-interchangeable with each other.
Across all listed years and positions, every bulb in the 500SEL side marker specification is a dual-filament type operating at 12V, consistent with standard automotive electrical system requirements.
The front and rear side marker sockets on the 1984-1985 500SEL both use BAY15d-based bulbs, P21/5W at the front and 3893 at the rear, though the differing wattage ratings between the two positions indicate they are intended for separate circuit functions.