Land Rover Defender 90 Back Up Light Bulb Size

The Land Rover Defender 90 back up light requires a bulb size of P21W for the rear lighting assembly. Data for the specified component covers the range from 1994 through 1997.

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
1997	P21W
1994-1995	P21W

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.	P21W

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Additional Notes

The P21W is the sole bulb type listed across all recorded model years of the Land Rover Defender 90 back up light specifications, covering 1994-1995 and 1997.
The P21W is an ECE-standard single-filament signalling bulb rated at 12 volts and 21 watts, designed primarily for signalling functions such as reverse lights.
The P21W uses a BA15s bayonet base, which is a single-contact bayonet fitting. The "s" in BA15s denotes a single contact pin, distinguishing it from the dual-contact BA15d variant, which is not interchangeable with this application.
The ECE designation on the P21W indicates compliance with the United Nations Economic Commission for Europe lighting regulations, a standard widely adopted across European and international vehicle markets.
Because the BA15s base is a keyed single-contact fitting, substituting a BA15d bulb would result in an incorrect fitment, as the pin configurations between the two base types differ.