Chevrolet Parkwood Back Up Light Bulb Size

The Chevrolet Parkwood back up light uses a 1156 bulb size for this model. The replacement chart covers 1959 to 1961 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.

Bulb Size by Year Range

Years	Bulb Size
1959-1961	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The 1156 is the sole bulb type listed for the Chevrolet Parkwood back up light across the 1959-1961 model years.
The 1156 is an ANSI-standardized bulb recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical specifications shared across those markets.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard automotive incandescent output for back up lighting of that era.
The 1156 uses a BA15s bayonet base, a single-contact mount where the "s" denotes a single pin, distinguishing it from the dual-pin BA15d variant with which it is not interchangeable.
The single-filament design of the 1156 means it produces one fixed level of output, as opposed to dual-filament bulbs that support two brightness levels for different functions.
Because the BA15s base relies on a twist-and-lock bayonet fitting rather than a threaded socket, substituting a screw-base bulb of otherwise similar wattage would not be physically compatible with the Parkwood's back up light housing.