Chevrolet Astro Map Light Bulb Size

The Chevrolet Astro map light utilizes bulb sizes 168 and 906 for interior illumination across various production periods. Available data covers the span from 1985 through 2005.

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
1996-2005	168
1985-1995	906

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 4.9W.	168
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 8W.	906

Other Locations

Additional Notes

The Chevrolet Astro uses two distinct bulb sizes for the map light across its production run: the 168 for model years 1996-2005 and the 906 for model years 1985-1995.
Both the 168 and 906 are ANSI-standardized miniature wedge bulbs sharing the T10 form factor and a 12-volt operating voltage, which places them in the same physical bulb family.
Despite sharing the T10 wedge base, the two bulbs differ in wattage. The 168 draws 4.9 watts, while the 906 draws 8 watts, making them electrically distinct from one another.
The higher wattage of the 906 means it produces more heat and draws more current than the 168. Substituting one for the other without accounting for this difference risks mismatched electrical load in the map light circuit.
Because both bulbs use the T10 wedge base, physical fitment alone does not confirm compatibility. The wattage difference is a relevant factor when evaluating whether one can serve as a replacement for the other.
The 1995 model year marks the transition point between the two bulb specifications, with 1995 and earlier requiring the 906 and 1996 and later requiring the 168.