The Eagle Summit front and rear turn signal bulbs both utilize a 1156 size bulb for replacement purposes. This replacement chart covers vehicle production spanning 1989 to 1992.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156 bulb is the sole turn signal bulb type specified for the Eagle Summit across all listed model years, covering both front and rear positions from 1989-1992.
The 1156 is a single-filament bulb, meaning it serves one lighting function only, which is consistent with its use in dedicated turn signal housings rather than combined stop/turn applications.
The 1156 operates at 12 volts and 21 watts, placing it within the standard low-voltage automotive electrical range typical of production vehicles from this era.
The bulb uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin, distinguishing it from the dual-contact BA15d base used in other automotive bulbs.
The 1156 carries ANSI standardization recognized in both the United States and Canada, indicating the specification conforms to a defined set of electrical and physical parameters shared across those markets.
Because the front and rear turn signal positions on the Eagle Summit share the same 1156 specification, a single bulb type serves all four turn signal sockets on the vehicle.
The BA15s bayonet base is not interchangeable with visually similar bases such as the BA15d, as the pin configuration differs and substitution would result in an improper fit.
The single-filament construction of the 1156 distinguishes it from the 1157, a physically similar bulb with a dual-filament design and BA15d base, which is incompatible with sockets designed for the 1156.