GMC Topkick Check Engine Bulb Size
GMC Topkick check engine bulb uses a 74 size bulb for this vehicle model. The replacement chart covers 1990 to 1998 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.
Bulb Size by Year Range
| Years | Bulb Size |
|---|---|
| 1990-1998 | 74 |
Bulb Specifications
| Description | Bulb Size |
|---|---|
| ANSI standard (US & Canada). Miniature wedge bulb (T5). 12V, 1.4W. | 74 |