The Plymouth Sapporo uses the 194 bulb for both front and rear side marker positions across the 1978-1983 model years.
The 194 is classified as a miniature wedge bulb, designated T10 in the international bulb sizing system, where "T" refers to the tubular shape and "10" indicates the width in eighths of an inch.
The 194 bulb operates at 12 volts with a power draw of 3.78 watts, placing it in the low-wattage range typical of marker and courtesy lighting applications.
The wedge base design of the 194 means the bulb is held in its socket by the tension of the base itself rather than by a separate metal contact pin, which is a common trait of T10 miniature bulbs.
The 194 conforms to ANSI standards recognized in both the United States and Canada, indicating a standardized specification for electrical and photometric performance.
Because the Plymouth Sapporo (1978-1983) uses the same 194 bulb in all four side marker positions, front and rear replacements are interchangeable with one another.