Jeep J20 front and rear side marker bulbs utilize 194 and 158 bulb sizes depending on location and model variation. The replacement chart covers 1974 to 1988 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Jeep J20 front side marker uses one of two bulb sizes across its model years: the 194 or the 158, both of which are ANSI-standard miniature wedge bulbs rated for 12 volts.
Both the 194 and 158 bulbs share the same T10 wedge base form factor, meaning they are physically interchangeable in terms of socket fitment.
Despite sharing the same T10 base, the 194 and 158 are not electrically identical. The 194 draws 3.78 watts, while the 158 draws 3 watts, a difference that affects output brightness.
The front side marker on the Jeep J20 uses the 194 bulb for the 1974-1982 model years, as well as for 1985-1988.
The 1983-1984 Jeep J20 front side marker departs from the surrounding model years by specifying the lower-wattage 158 bulb instead of the 194.
The rear side marker position on the J20 is specified only for the 1983-1984 model years, both of which use the 194 bulb.
The 194 bulb is the more widely used of the two types across the J20 side marker specifications, appearing in both the front and rear marker positions.
The T10 wedge base is a tool-free, push-in socket design, which is standard across both bulb types listed for this vehicle.