A top diagram will show the exact path from the battery (located in the trunk) through the B+ terminal, to the ignition switch, and then to these distribution boxes.
The original BMW TIS (now available as legacy software on DVD or online archives) contains the official wiring diagrams. These are vector-based, zoomable, and include full component locations. schema electrique bmw e39 top
) that uses hypertext links to navigate through navigation trees for specific nodes. Fuse & Relay Management: A top diagram will show the exact path