The International 1100D uses a 198 bulb size for both front and rear turn signal applications. This replacement chart covers vehicle production spanning 1969 to 1970.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The International 1100D uses the 198 bulb for both the front and rear turn signals across the 1969-1970 model years.
The 198 is an ANSI-standardized bulb, meaning it conforms to a defined set of electrical and physical specifications recognized across the United States and Canada.
The 198 bulb follows the T5 miniature wedge form factor, a design that uses the bulb's glass envelope itself as the base, eliminating a separate metal cap and allowing it to press directly into a compatible socket.
At 12 volts and 2 watts, the 198 is a low-power bulb, consistent with its role as a signal lamp rather than a primary illumination source.
The uniform application of the 198 bulb across both the front and rear positions on the International 1100D means a single bulb type serves all four turn signal positions on the vehicle.
The Light Duty designation associated with each fitment entry indicates these specifications apply to the light-duty variant of the 1100D, and fitment from other duty ratings should not be assumed interchangeable.