Mercedes-Benz 200D Map Light Bulb Size

Additional Notes

• The Mercedes-Benz 200D map light specifications cover model years 1966 through 1973, with two distinct bulb sizes used across that span.
• The 17053 is a Wagner part number designating a 12-volt halogen bulb intended for specialty applications, and it is the specified map light bulb for the 200D from 1968 through 1973.
• Halogen bulbs produce light by passing current through a tungsten filament enclosed in a halogen gas environment, which extends filament life and maintains lumen output compared to standard incandescent designs.
• The 12821 is a Philips part number designating a miniature wedge bulb in the T10 form factor, rated at 12 volts and 5 watts, and it is the specified map light bulb for the 200D in 1966 and 1967.
• The T10 form factor uses a W2.1x9.5d wedge base, meaning the bulb is held in its socket by the tension of the base contacts rather than by a bayonet or screw mechanism.
• The two bulb types are not interchangeable. The 17053 is a halogen specialty bulb while the 12821 is a miniature wedge type, and the two use fundamentally different base configurations.
• The change in specified bulb size between the 1967 and 1968 model years reflects a shift from the Philips 12821 to the Wagner 17053 for the map light position on the 200D.
• Both bulb types operate on a 12-volt electrical system, consistent with the standard automotive electrical architecture used in the 200D across all listed years.