Mack RB Courtesy Bulb Size
The Mack RB courtesy bulb utilizes 2 distinct sizes: 1003 and 912, with each bulb size corresponding to specific vehicle configurations. The replacement chart covers vehicle production spanning 1989 to 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 | 1003 |
| 1994-1996 | 912 |
| 1993 | 1003 |
| 1992 | 912 |
| 1991 | 1003 |
| 1989-1990 | 912 |
Bulb Specifications
| Description | Bulb Size |
|---|---|
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W. | 1003 |
| ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W. | 912 |