Freightliner Columbia Roof Marker Bulb Size

Additional Notes

• The Freightliner Columbia uses the 193 bulb for its roof marker lights across all specified model years from 2000-2017.
• The 193 is an ANSI-standardized bulb type, meaning its specifications are governed by a recognized North American standard applicable in both the United States and Canada.
• This bulb follows the T10 form factor, a miniature wedge-base design in which the base of the glass envelope itself acts as the retaining element, requiring no separate metal base or socket pins.
• The 193 operates at 12 volts, consistent with the standard electrical system voltage found in commercial vehicles.
• At 3.78 watts, the 193 draws relatively low power, which is characteristic of marker and clearance lighting applications where continuous operation is expected.
• Because the T10 wedge base is shared across numerous bulb part numbers, substitution with a physically similar bulb of a different wattage or voltage rating would not constitute a correct replacement for the 193 specification.