GMC C15 Suburban Turn Signal Bulb Size
The GMC C15 Suburban front and rear turn signal bulb sizes include 198, 1156, 1034, and 199 options, with the front position utilizing 198, 1156, or 199 bulbs and the rear position utilizing 198, 1156, or 1034 bulbs. The replacement chart covers 1967 through 1978 vehicle production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
Front Turn Signal
| Years | Bulb Size |
|---|---|
| 1973-1978 | 198 |
| 1971-1972 | 1156 |
| 1970 | 199 |
| 1969 | 1156 |
| 1967-1968 | 1073 |
Rear Turn Signal
| Years | Bulb Size |
|---|---|
| 1973-1978 | 198 |
| 1969-1972 | 1156 |
| 1968 | 1034 |
| 1967 | 1156 |
Bulb Specifications
| Description | Bulb Size |
|---|---|
| ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 2W. | 198 |
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W. | 1156 |
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 21W. | 199 |
| ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W. | 1073 |
| ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W. | 1034 |