The GMC K1500 side marker requires a 194 bulb size for proper installation and function within the lighting assembly. Data for the specified component covers the period from 1995 through 1999.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The two bulb types specified across the GMC K1500 side marker positions are the 194 and 168, both of which are ANSI-standard miniature wedge bulbs sharing the T10 form factor and a 12-volt operating voltage.
Although the 194 and 168 share the same T10 wedge form factor, they are not electrically identical. The 194 operates at 3.78 watts while the 168 operates at 4.9 watts, meaning the two types draw different amounts of current.
The 194 bulb is the more widely used of the two across the K1500 side marker specifications, appearing in both the front and rear side marker positions across the majority of model years covered.
Front side marker positions on the GMC K1500 used the 194 bulb from 1988-1999, with the exception of 1990 and 1991, where that fitment was conditional on the vehicle being equipped with halogen capsule headlamps.
For the 1990 and 1991 GMC K1500, the 194 front side marker fitment carries a headlamp system condition, indicating that vehicles without halogen capsule headlamps may require a different specification.
Front side marker positions on the GMC K1500 used the 168 bulb from 1979-1986, representing the earlier production period covered by these specifications.
The rear side marker position on the GMC K1500 is specified with the 194 bulb for 1979-1980 and again for 1993-1999, with no rear side marker data present for the years between those two ranges.
The T10 wedge base is a tool-free, push-in socket type, meaning bulb replacement in positions using either the 194 or 168 does not require a separate locking mechanism.