The GMC C1500 Suburban front side marker requires either a 194 or 168 bulb size, while the rear side marker uses a 194 bulb size. The replacement chart contains vehicle production years and bulb size specifications spanning 1979 to 1999.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The GMC C1500 Suburban uses two bulb types across its front and rear side marker positions: the 194 and the 168. Both are ANSI-standardized miniature wedge bulbs sharing the T10 form factor and a 12-volt operating voltage.
Although the 194 and 168 share the same T10 wedge base, they differ in wattage. The 194 draws 3.78W, while the 168 draws 4.9W, making them electrically distinct despite their physical similarity.
The shared T10 base between the 194 and 168 means the two bulbs can physically seat in the same socket, which presents an interchangeability risk. The wattage difference means one is not a direct electrical substitute for the other.
For the front side marker on the GMC C1500 Suburban, the 194 bulb is specified for model years 1992-1999, while the 168 bulb is specified for model years 1979-1986.
The rear side marker position uses the 194 bulb exclusively across all listed model years, which include 1979, 1985-1986, and 1993-1999.
The 194 bulb is the more widely used of the two types across the C1500 Suburban's side marker specifications, appearing in both front and rear positions across multiple model years.
The 168 bulb is limited to the front side marker position and does not appear in any rear side marker specification for this vehicle.
Both the 194 and 168 carry ANSI standardization recognized in both the United States and Canada, indicating consistent specification requirements across North American markets.