GMC K25 Turn Signal Bulb Size
GMC K25 front and rear turn signal bulbs utilize 198, 1156, 1073, and 199 sizes depending on location and model variation. The replacement chart covers 1967 through 1978 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
Front Turn Signal
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 |
|---|---|---|---|
| 1973-1978 | 198 | 198 | Check Price |
| 1969-1972 | 1156 | P21W | Check Price |
| 1967-1968 | 1073 | 1073 | Check Price |
Rear Turn Signal
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 |
|---|---|---|---|
| 1973-1978 | 198 | 198 | Check Price |
| 1972 | 199 | 199 | Check Price |
| 1969-1971 | 1156 | P21W | Check Price |
| 1968 | 1073 | 1073 | Check Price |
| 1967 | 1156 | P21W | Check Price |
Bulb Specifications
| Description | Type | Shop |
|---|---|---|
| ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 2W. | 198 | Check Price |
| 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. Lower wattage variant of 1156. 12V, 13W. | 1073 | Check Price |
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W. | 199 | Check Price |