Plymouth Champ front turn signal requires a 1157 bulb size while the rear turn signal uses a 1156 bulb size. The replacement chart covers 1979 to 1982 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Plymouth Champ uses two distinct bulb types across its turn signal system for the 1979-1982 model years, with the front and rear positions each requiring a different bulb.
The 1157 is a dual-filament bulb operating at 12V with a 21W main filament and a 5W secondary filament, mounted on a BAY15d bayonet base.
The BAY15d base on the 1157 features offset pins, which physically prevents it from being seated in a socket designed for a single-filament BA15s base.
The 1156 is a single-filament bulb rated at 12V and 21W, using a BA15s bayonet base with symmetrically placed pins.
Both the 1157 and 1156 are ANSI-standardized bulbs recognized in the United States and Canada.
The front turn signal position on the Plymouth Champ calls for the 1157 across all four model years covered in the specifications.
The rear turn signal position requires the 1156 for the same 1979-1982 span, a single-filament type rather than the dual-filament unit used at the front.
Because the 1157 and 1156 share the same 21W primary wattage, the wattage alone is not a reliable indicator of interchangeability between the two positions.