Pontiac Torpedo Back Up Light Bulb Size

The Pontiac Torpedo back up light requires a bulb size of 1129 for proper installation and function. Data for the specified component covers the period from 1950 to 1953.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1950-1953	1129

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.	1129

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Additional Notes

The Pontiac Torpedo uses the 1129 bulb across all four model years covered in these specifications, spanning 1950-1953.
The 1129 is an ANSI-standardized bulb recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical standards shared across those markets.
The 1129 is a dual-filament bulb, meaning it contains two separate filaments within a single envelope, each serving a distinct lighting function.
It uses a BAY15d bayonet base, a two-pin offset base type where the two pins are positioned at different heights to ensure the bulb can only be inserted in one orientation, preventing incorrect installation.
The 1129 operates at 12 volts, consistent with the 12-volt electrical systems standard in automotive applications of that era.
Its dual-filament power ratings are 21 watts and 5 watts, corresponding to the high and low output functions of the two filaments respectively.
The 1129 is listed as a variant of the 1157, a widely used automotive bulb that shares the same BAY15d base and dual-filament configuration, though the two types differ in their precise voltage and wattage ratings.