1990 BMW 325 Series Wiring Diagrams
Fig. 1: Engine Compartment & Headlights (Grid 1-3)
This diagram illustrates the wiring for the engine compartment and headlights of the 1990 BMW 325 Series, covering grids 1 through 3. It details connections for the battery, alternator, starter motor, lighting systems, and various control units.
Component Locator:
| Component | Location |
|---|---|
| A/C SYSTEM | A-E 16 |
| ABS CONTROL UNIT | A-B 20 |
| ABS HYDRAULIC UNIT | A-B 23 |
| ACTIVE CHECK CONTROL UNIT | D-E 20-23 |
| ALTERNATOR | C3 |
| AUTO CHARGING FLASHLIGHT | E 36 |
| AUXILIARY FAN BLOWER RESISTOR | C 12 |
| AUXILIARY FUSE BLOCK | D12 A |
| BACK-UP LT SW (M/T) | D 35 |
| BATTERY | A 2 |
| BATTERY JUNCTION BLOCK | A3 |
| BRAKE FLUID LEVEL SW | B 31 |
| CENTRAL LOCKING CONTROL UNIT | A-B 39 |
| CHIME MODULE | C 19 |
| CIG LTR | D 32 |
| COMBINATION SW | C-D 24 |
| COMPUTER HORN | E 17 |
| COMPUTER MODULE | D-E 19 |
| CONN #100 | D 10 |
| CONN #114 | D 10 |
| COOLANT TEMP SENDER | C9-10 |
| CRUISE CONTROL SW | E27 |
| CRUISE CONTROL UNIT | C-D 27 |
| DEFOGGER SW | E 40 |
| DIAGNOSTIC CONN | E 5-6 |
| DISTRIBUTOR | A4 |
| DOOR LOCKS | C-E 38-39 |
| DUAL TEMP SW | C 15 |
| FLASHER | E 25 |
| FOG LT RELAY | B 14-15 |
| FOG LT SW | C 24 |
| FRONT SEAT HEATERS | A 18-19 |
| FUEL PUMP | A7 |
| FUEL PUMP RELAY | B7 |
| FUEL TANK SENDER | B 42 |
| FUSE BLOCK | A-E 8-15 |
| GEAR SELECTOR SW (A/T) | C 35 |
| GLOVE BOX LT & SW | E 37 |
| HAZARD SW | E 24 |
| HI SPEED RELAY | B 13 |
| HIGH BEAM RELAY | D 10 |
| HORN RELAY | D9 |
| HORN SWS | D 33 |
| IGN COIL | A4 |
| IGN KEY SW | C18 |
| IGNITION SW | E 12-15 |
| INST CLSTR | A-E 28-30 |
| INTERIOR LT TIMER CONTROL | A 40 |
| INTERIOR LTS | A-B 40-42 |
| LIGHT SW | A-C 24 |
| LOW BEAM CHECK RELAY | C 11 |
| LOW BEAM RELAY | D 11 |
| LOW PRESSURE SW | A 18 |
| MAIN RELAY | C-D 7 |
| MAP READING LT | A8 |
| MOTRONIC CONTROL UNIT (MCU) | B-D 4 |
| MULTI-FUNCTION CLOCK (EX CONV) | D 19 |
| NORM SPEED RELAY | D9 |
| OIL LEVEL SENSOR | C-D 23 |
| OIL PRESSURE SW | B 31 |
| ON BOARD COMPUTER RELAY BOX | D 17 |
| PARK BRAKE SW | B 30 |
| POWER ANTΕΝΝΑ | D-E 36 |
| POWER MIRROR SW | C 32 |
| POWER WINDOW CB | A 37 |
| POWER WINDOWS (CONV) | A-B 32-35 |
| POWER WINDOWS (EX CONV) | A-D 36-37 |
| REAR LTS CHECK RELAY | A-B 27 |
| REAR WINDOW BLOWER RELAY | D 42 |
| SEAT BELT WARN TIMER | E 17 |
| STARTER MOTOR | B 3 |
| STARTER RELAY | E3 |
| STOP LT SW | A 26 |
| SUNROOF SW | D 40 |
| TRUNK LT | C 42 |
| UNLOADER RELAYS | B 13-14 |
| WASHER FLUID LEVEL SW | C 21 |
| WASHER MOTOR | E 33 |
| WIPER CONTROL UNIT | E 32 |
The diagram shows connections from the [Battery] (A2) and [Battery Junction Block] (A3) to various components. Key systems include the [Alternator] (C3), [Starter Motor] (B3), and lighting circuits. It also depicts relays for the [Fuel Pump] (B7), [Horn] (D9), and headlights. Wire colors like Red, Black, Brown, Blue, Yellow, and Gray are used to denote different circuits.
Fig. 2: Computer Engine Control (Grid 4-7)
This diagram focuses on the computer engine control system for the 1990 BMW 325 Series, spanning grids 4 to 7. It shows the connections for the Motronic control unit (MCU), airflow meter, various sensors (oxygen, coolant temperature, intake air temperature), and engine speed/identification sensors.
Key components include the [Distributor], [Cylinder Identification Sensor], [Airflow Meter], and the Motronic Control Unit (MCU). The diagram illustrates inputs from sensors like [Oxygen Sens], [Coolant Temp Input], and [Air Inlet Temp], as well as outputs to systems like the [Fuel Pump Relay Ctrl] and [Fuel Injectors]. Wire colors include Green, Brown, Black, Yellow, Gray, and Red.
Fig. 3: Fuse Block (Grid 8-11)
This diagram details the fuse block layout and connections for the 1990 BMW 325 Series, covering grids 8 through 11. It illustrates the fuses, relays (K1-K4), and their associated circuits for various components like horns, headlights, and auxiliary systems.
The diagram shows the main fuse block with numbered fuse slots and corresponding amperage ratings (e.g., 7.5A, 15A, 30A). It depicts relays such as [K1 Norm Speed Rly], [K2 Horn Relay], [K3 High Beam Relay], and [K4 Low Beam Relay]. Connections are shown to components like [Horns], [Right Hi Beam Headlight], [Left Lo Beam Headlight], and the [Active Check Ctrl Unit]. Wire colors include Violet, Green, Brown, Black, and Yellow.
Fig. 4: Fuse Block (Continued) (Grid 12-15)
This diagram continues the illustration of the fuse block for the 1990 BMW 325 Series, covering grids 12 to 15. It shows additional relays (K5-K8) and fuse connections for systems such as unloader relays, high-speed relays, fog light relays, power windows, and interior lighting.
This section details relays like [K5 Unloader Relay], [K6 Hi Speed Relay], [K7 Unloader Relay], and [K8 Fog Lt Relay]. It shows fuse connections for systems including [Power Wdo CB], [Interior Lt Timer Ctrl], [Auxiliary Fan], and various lighting circuits like [Right Fog Lt] and [Left Fog Lt]. Wire colors include Black, Green, Red, Brown, Gray, and Violet.
Fig. 5: A/C & Heating and Accessories (Grid 16-19)
This diagram covers the Air Conditioning (A/C) and heating systems, along with various accessories for the 1990 BMW 325 Series, within grids 16 to 19. It details blower motors, resistors, switches, seat heaters, and connections to the On Board Computer relay box.
The diagram illustrates the [Blower Resistors], [Blower Motor], [Evap Temp Regulator], and [A/C Ctrl SW]. It also shows connections for [Front Seat Heaters], [Horn Relay], [Computer Horn], and the [On Board Computer Relay Box]. Key wire colors include Yellow, Blue, Black, Green, Brown, Violet, and Red.
Fig. 6: Anti-Lock Brake System (Grid 20-23)
This diagram illustrates the Anti-Lock Brake (ABS) System for the 1990 BMW 325 Series, spanning grids 20 to 23. It shows the ABS control unit, hydraulic unit, wheel speed sensors, and related relays and warning indicators.
This section details the [ABS Control Unit], [ABS Hydraulic Unit], and various wheel speed sensors ([Left Fnt Wheel Speed Input], [Left Rear Wheel Speed Input], [Rt Fnt Wheel Speed], [Rt Rear Wheel Speed]). It includes connections for the [Main Relay], [Pump Rly Ctrl], and warning indicators such as [ABS IND CTRL]. Wire colors include Red, Yellow, Green, Brown, Black, and Blue.
Fig. 7: Steering Column and Cruise Control (Grid 24-27)
This diagram details the wiring for the steering column and cruise control system of the 1990 BMW 325 Series, covering grids 24 to 27. It includes connections for lighting switches, hazard switch, defogger switch, and the cruise control actuator and unit.
The diagram shows connections for various switches including [Light SW], [Hazard SW], [Defogger SW], and [Stop LT SW]. It illustrates the [Cruise Control Actuator] and [Cruise Control Unit], with inputs for [Resume Speed], [Accel/Set], and [Vehicle Speed Input]. Wire colors include Gray, Green, Red, Brown, Black, Blue, and Violet.
Fig. 8: Instrument Panel (Grid 28-31)
This diagram illustrates the instrument panel and its associated wiring for the 1990 BMW 325 Series, within grids 28 to 31. It shows connections for the instrument cluster, gauges (fuel, tachometer), warning lights (ABS, check engine, brake), and various sensors.
This section details the [Instrument Cluster] with its numerous pins (A1-A26, B1-B26, C1-C26). It shows connections to the [Starter Motor], [MCU PIN #6], [Alternator], [Fuel Tank Sender], [Brake Warning Indicator], [Check Engine Indicator], and [ABS Indicator]. Wire colors include Black, Green, Red, Brown, Yellow, Blue, Gray, and Violet.
Fig. 9: Accessories (Grid 32-35)
This diagram covers various accessories for the 1990 BMW 325 Series, within grids 32 to 35. It details power window console switches, motors, power mirror switches, horn switches, cigarette lighter, wiper motor, and washer switches.
The diagram illustrates [Power Mirror SW], [Horn Switches], [Cigarette Lighter], [Wiper Motor], and [Washer Motor]. It shows connections for [Left Front Window Console SW], [Right Front Window Console SW], [Left Rear Window Console SW], and [Right Rear Window Console SW], along with their respective [Window Motors]. Wire colors include Black, Brown, Blue, Green, Yellow, Violet, and Red.
Fig. 10: Power Windows & Power Locks (Grid 36-39)
This diagram illustrates the power windows and power locks systems for the 1990 BMW 325 Series, spanning grids 36 to 39. It shows the control units, motors for each window and door lock, and associated switches and safety interlocks.
This section details the [Central Locking Control Unit] and its functions for [Lock Control] and [Unlock Control]. It shows connections to [Left Front Window Motor], [Left Rear Window Motor], [Right Front Window Motor], and [Right Rear Window Motor], as well as [Driver Door Lock Motor] and [Right Rear Door Lock Motor]. It also includes the [Interior Lt Timer Ctrl] and [Unlock Inhibitor SW]. Wire colors include Violet, Brown, Blue, Green, Red, Black, and Yellow.
Fig. 11: Passenger Compartment & Taillights (Grid 40-43)
This diagram covers the passenger compartment lighting and taillight systems for the 1990 BMW 325 Series, within grids 40 to 43. It details dome lights, trunk lights, rear window blower, sunroof motor, and taillight assemblies.
The diagram illustrates connections for [Dome Light], [Trunk LT], [Rear Window Blower], and [Sunroof Motor]. It shows the [Taillight Assemblies] including [Left Taillt Assy] and [Right Taillt Assy], and their respective lights ([Marker Light], [Stop LT], [Turn LT], [Back-Up Light]). It also depicts the [Interior Light Timer Control] and [Hazard SW]. Wire colors include Brown, Violet, Red, Green, Gray, Blue, and Black.
