Plymouth Sundance headlight bulbs utilize 9004 and H4666 sizes for both high and low beam functions. The replacement chart covers 1987 to 1994 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 Plymouth Sundance uses two distinct headlight technologies across its model years. The 1987-1988 model years use the H4666, a rectangular sealed beam unit, while the 1989-1994 model years use the 9004, a halogen bulb with a replaceable filament assembly.
The 9004 is a dual-filament halogen bulb operating at 12 volts, with a high beam output of 65 watts and a low beam output of 45 watts. It uses a P29t base and conforms to ANSI standards recognized in both the United States and Canada.
On the Plymouth Sundance, the 9004 bulb serves both the high beam and low beam functions within a single unit. This is a characteristic of dual-filament bulbs, where one filament handles each lighting mode.
The H4666 is a sealed beam unit rather than a replaceable bulb. When this unit fails, the entire assembly is replaced rather than an individual filament or bulb component. It operates at 12 volts and also meets ANSI standards for the United States and Canada.
The H4666 sealed beam format and the 9004 halogen bulb are not interchangeable. The transition between these two types across the 1988 and 1989 model years reflects a change in headlight housing design, meaning parts from one generation are not compatible with the other.
Both the H4666 and the 9004 share the same high beam and low beam bulb size across their respective model years, indicating that the Plymouth Sundance does not use separate bulb types for each beam function in either generation.