Ford EXP Back Up Light Bulb Size

The Ford EXP back up light utilizes 1156 and P21W bulb sizes for the rear illumination system. Data for the specified lighting components covers the period from 1982 through 1988.

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
1982-1988	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Ford EXP uses the 1156 bulb for the back up light across all listed model years, spanning 1982-1988.
The 1156 is an ANSI-standardized bulb type, meaning its specifications are governed by a recognized North American standard applicable in both the United States and Canada.
This bulb operates on a 12-volt electrical system, which is consistent with standard automotive DC voltage.
The 1156 carries a 21-watt rating, placing it in the mid-range of incandescent automotive bulb wattages.
It is a single-filament bulb, meaning it serves one lighting function only, as opposed to dual-filament types that handle two functions such as braking and running light simultaneously.
The 1156 uses a BA15s bayonet base, where "BA15s" denotes a bayonet mount with a 15mm base width and a single contact pin.
The single-contact BA15s base is not interchangeable with the BA15d base, which carries two offset contact pins and is found on dual-filament bulbs such as the 1157.