Mercury Montclair Courtesy Bulb Size
The Mercury Montclair courtesy light uses bulb sizes 631, 1816, 1003, 89, and 63 depending on the specific application. Data for the light covers the span from 1955 to 1968.
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 |
|---|---|
| 1968 | 631 |
| 1967 | 1816 |
| 1966 | 631 |
| 1965 | 1003 |
| 1964 | 631 |
| 1958-1960 | 89 |
| 1955 | 63 |
Bulb Specifications
| Description | Bulb Size |
|---|---|
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W. | 631 |
| ANSI standard (US & Canada). Miniature wedge bulb (T3.25). 12V, 4W. | 1816 |
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W. | 1003 |
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W. | 89 |
| ANSI standard (US & Canada). Single-filament bulb with BA9s base. 12V, 0.63W. | 63 |