Peterbilt 359 Dome Light Bulb Size

The Peterbilt 359 dome light requires a bulb size of 97 for the interior lighting fixture. Data for the specified component covers the period from 1986 through 1988.

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
1986-1988	97 (With 2 Rectangular Headlamps)

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	97

Other Locations

Additional Notes

The bulb size 97 is the specified dome light bulb for the Peterbilt 359 across the 1986-1988 model years, applicable to configurations with 2 rectangular headlamps.
The 97 bulb follows the ANSI standard recognized in both the United States and Canada, classifying it as a standardized automotive bulb within North American markets.
As a single-filament bulb, the 97 operates one circuit, which is typical of lighting functions that require a constant, non-variable output such as dome illumination.
The 97 uses a BA15s bayonet base, a single-contact mount where the "s" denotes a single pin, distinguishing it from dual-contact bayonet variants that would not seat correctly in the same socket.
The 97 is a variant of the 1156 bulb. While the two share a BA15s base, they are not electrically identical, and substituting one for the other without confirming voltage and wattage compatibility may affect circuit performance.
The 97 bulb operates at 12 volts and draws 13 watts, placing it within the standard low-voltage electrical architecture common to commercial trucks of this era.