Peterbilt 377 Courtesy Bulb Size

The Peterbilt 377 courtesy light utilizes unique bulb sizes 1004, 1141, 906, and P21W to provide illumination for the interior cabin area of the heavy duty truck. Available data for the specified lighting components spans a range from 1987 through 1997 to assist with identifying the correct replacement for the vehicle.

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

YearsBulb Size
1997P21W
1004 (With 4 Round Headlamps)
19961141
19951004
1141 (With Halogen Capsule Headlamps)
19941141 (With 4 Rectangular Headlamps)
906 (With 4 Round Headlamps)
P21W (With Halogen Capsule Headlamps)
19931141
1004 (With 4 Round Headlamps)
1992P21W
906 (With 4 Round Headlamps)
19911004
1141 (With 4 Rectangular Headlamps)
19901004
1141 (With 4 Round Headlamps)
19891141
19881004
1141 (With 4 Round Headlamps)
19871141
1004 (With 4 Round Headlamps)

Bulb Specifications

Description Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.P21W
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Variant of 1157. 12V, 21/5W.1004
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.1141
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 8W.906

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