Mack F Back Up Light Bulb Size
The Mack F back up light requires bulb size 1156 or P21W depending on the specific configuration of the vehicle. Data for the lighting components covers the range from 1981 to 1982.
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 | US Type | EU Type | Shop |
|---|---|---|---|
| 1981-1982 | 1156 | P21W | Check Price |
Bulb Specifications
| Description | Type | Shop |
|---|---|---|
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W. | 1156 | Check Price |
| ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W. | P21W | Check Price |