GMC C25 Back Up Light Bulb Size
GMC C25 back up light bulb utilizes 1156 and 199 size bulbs for this truck model. The replacement chart covers vehicle production spanning 1973 to 1978 with corresponding bulb size data.
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
If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.
| Years | US Type | EU Type | Shop |
|---|---|---|---|
| 1977-1978 | 1156 | P21W | Check Price |
| 1976 | 199 | 199 | Check Price |
| 1973-1975 | 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 |
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W. | 199 | Check Price |