Mack RW Courtesy Bulb Size
The Mack RW courtesy bulb uses 2 distinct sizes: 912 and 1003, with each bulb size corresponding to specific vehicle configurations. The replacement chart covers 1985 through 1993 production years and documents the applicable bulb sizes for this model.
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 |
|---|---|
| 1992-1993 | 912 |
| 1989-1991 | 1003 |
| 1985-1988 | 912 |
Bulb Specifications
| Description | Bulb Size |
|---|---|
| ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W. | 912 |
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W. | 1003 |