The Jeep J-3800 front turn signal bulb size measures 1156 or 1034, while rear turn signal bulb size measures 1156, 199, or 1034. The replacement chart covers 1965 through 1971 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 J-3800 front turn signal uses the 1034 bulb for model years 1965-1968 and transitions to the 1156 bulb for 1969-1971.
The 1034 is a dual-filament bulb rated at 12V and 21/5W, fitted with a BAY15d bayonet base, and is classified as a variant of the 1157 under the ANSI standard applicable in the US and Canada.
The dual-filament design of the 1034 means it serves two electrical circuits through a single housing, with the two wattage ratings corresponding to each filament independently.
The 1156 is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base, and carries ANSI standard designation for the US and Canada.
The BA15s base of the 1156 differs from the BAY15d base of the 1034. These two base types are not interchangeable, as the pin offset and alignment of BAY15d prevents incorrect installation of a dual-filament bulb in a single-filament socket.
The Jeep J-3800 rear turn signal for 1969 uses the 199 bulb, while the front turn signal for the same year uses the 1156, making 1969 the only model year where the front and rear turn signals specify different bulb types.
The 199 is a single-filament bulb rated at 12V and 21W with a BA15s bayonet base, and is classified as a variant of the 1156 under the ANSI standard.
Because the 199 shares the same base type, voltage, and wattage as the 1156, the two are functionally and physically compatible in sockets designed for either designation.
The rear turn signal for 1970-1971 uses the 1156, aligning with the front turn signal specification for those same years.
For 1965-1968, both the front and rear turn signals of the J-3800 specify the same 1034 bulb, indicating a uniform fitment across both positions during that period.