The genuine BMW yellow plug housing (part number 61131378403) primarily fits the 1985–1989 BMW 635CSi and the 1987–1988 BMW M6 (E24 chassis). These may also fit E34 and E32 models...see below. Check to be sure.This specific part is a 2-pole electrical connector housing (internally designated by BMW as Gelb, meaning yellow). Its primary purpose is to protect and secure the wiring pins that plug directly into individual components in the engine bay. (9g)
While it can act as a universal connector for small 2-pin electrical components, its primary uses across classic BMWs include:
1. Low-Beam Headlight Power Connection - On classic chassis like the E24 (6 Series) and E34 (5 Series), BMW used color-coded plug housings on the back of the Euro-spec or standard Hella headlight assemblies to help mechanics identify the correct wiring line. The yellow plug (...403) is most commonly assigned to connect power to the low-beam headlights. Note: It sits alongside the black housing (61131378402) and standard housing (61131378401), which handle the parking lights and high beams respectively.
2. Windshield Washer Fluid Pumps - In several models, this same 2-pin keyed plug is used to snap onto the prongs of the windshield or intensive-cleaning headlight washer pump mounted directly on the plastic fluid reservoir.
3. Turn Signal Indicators - On specific European-spec models and certain trim lines, this connector feeds power directly to the front turn signal indicator assemblies or side marker housings.
6 Series (E24 Chassis)
5 Series (E34 Chassis)
7 Series (E32 Chassis)
