GMC Savana Map Light Bulb Size

The GMC Savana map light bulb size chart specifies 2 distinct bulb sizes: 578 and 561 for this vehicle model. The replacement chart covers vehicle production spanning from 1996 to 2020.

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
2003-2020	578
1996-2002	561

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V, 12W.	578
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561

Other Locations

Additional Notes

The GMC Savana map light uses the 578 bulb for model years 2003-2020 and the 561 bulb for model years 1996-2002.
Both the 578 and 561 are festoon-type bulbs, meaning they are cylindrical in shape and make electrical contact through metal caps at each end rather than through a base socket.
Both bulbs share identical electrical ratings of 12 volts and 12 watts, making them equivalent in power draw and brightness output.
The physical distinction between the two bulbs is their length. The 578 measures 41mm, while the 561 measures 44mm. This 3mm difference makes them non-interchangeable despite their identical voltage and wattage ratings.
Installing a 561 in a housing designed for a 578 risks a poor or intermittent contact fit, as the longer bulb may not seat correctly within the shorter festoon holder.
Both bulbs conform to ANSI standards applicable in the United States and Canada, indicating standardized construction and performance tolerances across manufacturers.
The 578 bulb is the specification for the GMC Savana across a longer portion of its production span, covering eighteen model years from 2003 through 2020.
The 561 bulb applies to the GMC Savana across seven model years from 1996 through 2002.