The Pontiac Chieftain front and rear turn signal bulbs utilize either 1034 or 1154 size bulbs depending on production specifications. The replacement chart covers 1950 through 1958 model years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Pontiac Chieftain uses two bulb types across its turn signal positions: the 1034 for model years 1955-1958 and the 1154 for model years 1950-1954.
Both the 1034 and 1154 are ANSI-standardized bulbs recognized in the United States and Canada, and both share the BAY15d bayonet base, a double-contact base with two offset pins that prevent incorrect insertion.
Both bulbs are dual-filament types, meaning a single bulb contains two separate filaments that serve different lighting functions simultaneously within the same housing.
The 1034 operates at 12 volts with a 21/5W dual-filament output, where the higher wattage filament handles the turn signal function and the lower wattage filament handles a secondary function such as parking or running light duty.
The 1154 is rated for either 6V or 12V operation, reflecting its origin in an era when automotive electrical systems were transitioning from 6-volt to 12-volt standards.
The 1034 is described as a variant of the 1157, which is a widely used modern dual-filament bulb. The 1154 is described as an older variant of the same 1157 lineage, placing both bulbs within the same general family of bayonet-base dual-filament bulbs.
Despite sharing the same BAY15d base, the 1034 and 1154 are not confirmed as interchangeable, as differences in voltage rating and wattage output distinguish the two bulbs within the specifications.
The front and rear turn signal positions on the Pontiac Chieftain use identical bulb sizes for each given model year, with no distinction between front and rear fitment across any of the listed years.