BMW 325i 1989 User Manual

Step-by-step guide for diagnosing electrical issues in the vehicle.

Detailed explanations of various electrical diagnostic tests.

Procedure to measure voltage drop across a circuit to identify faults.

Method for checking electrical continuity in circuits using an ohmmeter.

Technique to locate shorts in electrical circuits with a voltmeter.

Procedure to identify shorts in circuits using an ohmmeter.

Diagram illustrating the main power distribution pathways and components.

Schematic detailing relay connections and associated power circuits.

Wiring diagram for the charging system, including alternator and battery.

Schematic showing the starter motor and ignition switch wiring.

Wiring diagram for the starter system specific to manual transmissions.

Schematic showing air flow meter, engine load, and related sensor wiring.

Wiring for the main relay and fuel pump control circuits.

Schematic showing fuel injectors and cylinder identification sensor wiring.

Wiring for check engine light and transmission control systems.

Schematic showing ignition switch and computer interface wiring.

Wiring diagram for the distributor and ignition coil.

Schematic for fuel pump relay and engine control unit connections.

Wiring for fuel injectors, oxygen sensors, and other engine sensors.

Schematic showing A/C controls, throttle position sensor wiring.

Wiring for brake fluid level and brake pad wear warning indicators.

Schematic for the ABS system in early production models.

Wiring for the ABS hydraulic unit and wheel speed sensors.

Schematic for the ABS system in late production models.

Wiring for the ABS pump motor and valve control circuits.

Schematic showing ABS wheel speed detector connections.

Steps for checking the central locking system's operation.

Table correlating system responses to required repair actions.

Continuation of system check procedures and response/repair actions.

Diagnostic tests for the central locking system.

Tests for the central locking control unit and fused jumpers.

Diagnostic tests for central locking unlock functions.

Wiring for the speedometer and various indicator lights.

Schematic for fuel level and coolant temperature gauges.

Wiring for high beam and fog light relays.

Schematic for low beam headlights and indicator lights.

Wiring for the hazard light switch and flasher unit.

Schematic for turn signal light circuits.

Schematic for brake light switch and rear stop light assemblies.

Schematic of the A/C temperature control panel and its functions.

Explanation of the water shut-off solenoid and its role in the HVAC system.

Diagnostic tests for the water shut-off solenoid.

Wiring for the A/C blower speed control switches.

Tests for voltage at the A/C control switches.

Tests for voltage at the blower motor control connector.

Tests to diagnose blower motor operation and resistance.

Schematic for fresh/recirculating air flap door control.

Wiring for the flap door motor control and relays.

Tests for voltage at the fresh/recirculating air relay.

Tests for voltage at the A/C control switches.

Schematic for A/C control panel and evaporator temperature sensor.

Wiring for the A/C compressor clutch and pressure cut-out switches.

Explanation of A/C compressor operation and related controls.

Diagnostic tests for A/C compressor system issues.

Tests to isolate faults in the A/C system.

Tests for resistance in pressure switches.

Tests for voltage at the evaporator temperature sensor.

Tests for voltage at the idle speed control unit.

Tests for voltage at the A/C selector switch.

Schematic for the cruise control system.

Wiring connecting the on-board computer to the instrument cluster.

Schematic showing inputs and outputs for the on-board computer.

Diagram and table of pins, wire colors, and connected components.

View of the engine speed sensor connector.

Views of Motronic control unit connectors.

View of the throttle switch connector.