This electrical wiring diagram is applicable for the following BMW models: 316 (83 to 88), 316i (88 to 91), 318i (83 to 91), 320i (87 to 91), 325i (87 to 91), also Touring and Convertible versions of these models; 5-Series (E28) 518 (81 to 85), 518i (85 to 88), 525i (81 to 88), 528i (81 to 88), 535i (85 to 88), M535i (85 to 88); 5-Series (E34) 518i (90 to 91), 520i (88 to 91), 525i (88 to 91), 530i (88 to 91), 535i (88 to 91); Engines covered 1596 cc, 1766 cc, 1795 cc, 1990 cc, 2494 cc, 2788 cc, 2986 cc & 3430 cc. This manual does not cover Diesel, dohc or V8 engines, or four-wheel-drive models. Here you will find complete description and illustration of BMW 3- and 5- Series Body Electrical Wiring Diagram. This manual is divided into 19 sections in which each section representing a specific function or electrical components.
Section 1 contains general information of the electrical system, the chassis electrical system of this vehicle is of 12-volt, negative earth type. Power for the lights and all electrical accessories is supplied by a lead/acid-type battery, which is charged by the alternator.
Section 2 contains electrical system fault finding, here you will be guided on pinpointing electrical circuit problem where electrical wiring diagrams are included at the end of this manual. This troubleshooting includes guidance on how to perform voltage checks, finding a short-circuit, earth check, continuity checks and finding an open-circuit.
Section 3 contains information on the fuses; generally the electrical circuits of the vehicle are protected by a combination of fuses and circuit breakers. The fuse box is located in the left corner of the engine compartment. On some later models, it is located under the rear seat cushion.
Download the complete BMW 3 and 5 Series Body Electrical Wiring Diagram here (33 pages of pdf filetype documents)