Freightliner 114SD Roof Marker Bulb Size

Additional Notes

• The Freightliner 114SD uses the 193 bulb size for its roof marker lights across the 2012-2018 model years.
• The 193 bulb is a miniature wedge type with a T10 base, which refers to the tubular glass envelope width measured in eighths of an inch, making it a relatively small-profile lamp.
• This bulb operates at 12 volts and draws 3.78 watts, placing it in the low-wattage range typical of marker and clearance lighting applications.
• The 193 designation follows the ANSI standard recognized in both the United States and Canada, meaning it conforms to a defined set of electrical and physical parameters shared across compliant manufacturers.
• The T10 wedge base design does not use a separate metal base or pins; instead, the glass envelope itself is pinched at the bottom to form the contact points, which is a common construction for low-current marker lamps.
• Because the 193 is an ANSI-standardized wedge bulb, other bulbs sharing the same T10 wedge base and 12V rating may physically fit the socket, though wattage differences can affect circuit compatibility and light output.