Polaris Wide Trak Brake Bulb Size

The Polaris Wide Trak brake requires 921 and 1157 bulb sizes for the lighting system. Data for the specified components covers the range from 1991 through 1993.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1993	921
1991-1992	1157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157

Other Locations

Additional Notes

The 1157 bulb is a dual-filament type rated at 12V with a 21W/5W output, using a BAY15d bayonet base. The two filaments serve separate functions, with the higher-wattage filament typically dedicated to braking and the lower-wattage filament to running light operation.
The 921 bulb is a single-filament wedge type in a T15 form factor, rated at 12V and 16W. Unlike the 1157, it lacks a bayonet base and is retained by the tension of its socket rather than a twist-lock mechanism.
Both bulb types conform to ANSI standards recognized in the United States and Canada, indicating standardized electrical and physical specifications within those markets.
The Polaris Wide Trak used the 1157 bulb for the 1991-1992 model years and transitioned to the 921 bulb for the 1993 model year. These two bulbs are not interchangeable due to differences in base type, filament count, and wattage.
The shift from the BAY15d bayonet base of the 1157 to the wedge base of the 921 means the socket design differs between the 1991-1992 and 1993 model years, making cross-year bulb substitution physically incompatible without socket modification.