Polaris 500 Brake Bulb Size

The Polaris 500 brake bulb specifications include 3 distinct sizes: 3157, 921, and 90, with each size corresponding to particular applications on the vehicle. A replacement chart documents brake bulb specifications across the 1989 to 2006 production range for the Polaris 500.

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
2006	3157
1993-2005	921
1989-1992	90

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3157
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 13W.	90

Other Locations

Additional Notes

The brake bulb specifications for the Polaris 500 span three distinct bulb types across the 1989-2006 model range: the 90, 921, and 3157.
The 921 is the most frequently specified brake bulb, covering the Polaris 500 from 1993-2005. It is a single-filament wedge bulb in the T15 form factor, rated at 12V and 16W, and conforms to the ANSI standard used in the United States and Canada.
The 3157 is specified exclusively for the 2006 model year. Unlike the 921, it is a dual-filament T25 wedge bulb rated at 12V with a 27W main filament and a 7W secondary filament, which allows it to serve both brake and running light functions from a single bulb.
The 90 bulb is specified for the 1989-1992 model years. It is a single-filament bulb rated at 12V and 13W, and it uses a BA15s bayonet base rather than a wedge-style base, making it physically incompatible with the sockets designed for the 921 or 3157.
The transition from the 90 to the 921 between the 1992 and 1993 model years represents a base-type change. The BA15s bayonet mount of the 90 and the wedge mount of the 921 are not interchangeable, and substitution between these two types is not supported by the specifications.
The 921 and 3157 both use wedge-style bases, but their T15 and T25 form factors differ in physical size. The 3157 also carries a higher wattage on its primary filament, and the two bulbs are not listed as interchangeable within these specifications.