The BMW 325ix was produced from 1988 to 1991, and featured all-wheel drive. It was available as a two-door (saloon) or a four-door (sedan) and as touring. The bmw 325iX wiring diagram electrical schematics following article provides detail procedures for maintaining, inspection, trouble diagnose, and repairing the 1990 BMW 325iX Electrical System.

This manual is divided into following sections: Index, How to Use This Manual, Wire Size Conversion Chart, Wiring Diagram and Electrical Parts Symbols, Systematic Troubleshooting, Connector Views, Power Distribution Box, Fuse Data, Component Location Chart, Component Location View, and Splice Locations Views.

This manual also covers topics on: Power Distribution System, Charging and Starting System, Electronics Injection System, Supplemental Restraint System, Brake Warning System, Antilock Braking System, Power Mirror, Central Locking, Power Windows, Seats, Sunroof, Body Electrical System, Wiper and Washer, Instrument Cluster, Active Check Control, Light Switch Details, Headlight, Turn and Hazard Lights, Heating and Air Conditioning, Radio, Antenna and Power Antenna, etc. Here is a quotation from the voltage drop testing section.

“Wires, connectors and switches are designed to conduct current with a minimum loss of voltage. A voltage drop of more than one volt indicates a problem. To test a voltage drop, connect the voltmeter leads to connectors at either end of circuit’s suspected problem area. The positive lead should be connected to the connector closest to the power source. The voltmeter will show the voltage drop between these two points.”

Find more information about 1990 BMW 325iX Electrical Troubleshooting Manual – Harness and Schematics here. (source:,

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