Mack CM Back Up Light Bulb Size
The Mack CM back up light utilizes P21W and 1156 bulb sizes for the rear illumination system. Data for the specific components covers the period from 1988 through 1991.
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 |
|---|---|---|---|
| 1988-1991 | 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 |