🏷️ Basic Information Identification Make: BMW Model: 3 Series Model Variant: 325, 325i, 325is Year: 1988 Codes Chassis Code: E30 Engine Code Common: M20B27 👋 Introduction Market Position Target Audience: BMW enthusiasts, independent mechanics, and DIY repairers working on 1988 E30 3 Series models. Value Proposition: Essential resource for diagnosing and resolving complex electrical issues, saving time and money on repairs. Competitive Analysis Competitors: Other generic repair manuals or unofficial online forums, which may lack the specific detail and accuracy of this specialized manual. Key Features Specialization: Focuses exclusively on the electrical systems of the 1988 325, 325i, and 325is, offering unparalleled depth. Comprehensiveness: Covers all styles and electrical aspects, ensuring no crucial information is missing. 📋 Manual Details Coverage Areas Manual Type: Electrical Troubleshooting Manual Language: English Format: Printed Document (likely spiral-bound for lay-flat use) Completeness: 100% Complete and Intact 📖 Manual Coverage Systems Covered Electrical Systems Main: All electrical systems for 1988 BMW 325, 325i, and 325is models. Engine Management Electrical: Engine control unit (ECU), fuel injection system (likely Motronic), ignition system. Lighting System: Headlights, taillights, interior lights, turn signals, brake lights, fog lights (if equipped). Instrumentation And Gauges: Speedometer, tachometer, fuel gauge, oil pressure warning light, coolant temperature gauge, warning indicators. Power Accessories: Power windows, power locks, power mirrors, sunroof (if equipped). HVAC Electrical: Blower motor, climate control unit, A/C compressor clutch wiring. Audio System: Factory radio wiring, speaker connections, antenna. Starting And Charging: Starter motor, alternator, battery, ignition switch. Wiper And Washer: Wiper motor, washer pump, controls. Cruise Control Electrical: Actuator, control module, switches (if equipped). ABS Electrical: ABS control module, wheel speed sensors, hydraulic unit (if equipped with ABS). Procedures Included Troubleshooting Methodology: Systematic diagnostic procedures, symptom-based troubleshooting flowcharts. Wiring Diagrams: Detailed, model-specific wiring schematics for all covered systems. Component Testing: Testing procedures for relays, switches, motors, sensors, and electronic modules using multimeters and oscilloscopes. Fuse And Relay Identification: Location and function of all fuses and relays. Connector Pinouts: Detailed pin identification for various electrical connectors. Common Faults: Identification and diagnosis of frequent electrical issues specific to the E30 platform. Technical Depth Depth Level: Comprehensive diagnostic and repair guidance for electrical faults. Diagnostic Tools: Guidance on using common diagnostic tools like multimeters, test lights, and continuity testers. Circuit Tracing: Detailed instructions for tracing electrical circuits and identifying breaks or shorts. 📊 Manual Specifications File Format File Type: Print Digital Compatibility: Not specified as digital, assumed physical copy. Print Quality Paper Quality: High-quality paper, likely durable for workshop use. Print Clarity: Clear and legible text and diagrams. Binding Type Binding: Likely spiral-bound or perfect-bound for durability and ease of use. ⚙️ Engine Specifications Primary Engine Engine Type: Inline 6-cylinder Engine Code: M20B27 (commonly designated as 'eta' for efficiency tune in 325e, but 325i/is typically used a higher-output variant, often with revisions to the M20). Displacement Cc: 2693 cc Bore X Stroke Mm: 84.0 mm x 81.0 mm Performance Horsepower Hp Est: 168 hp @ 5800 rpm (for 325i/is, 'eta' variants were typically lower) Torque Lb Ft Est: 164 lb-ft @ 4250 rpm (for 325i/is) Fuel System Fuel Injection System: Bosch Motronic (likely Motronic 1.3 or similar) Fuel Type: Unleaded Premium Gasoline (91 octane or higher) 🔧 Transmission Standard Transmission Type: 5-Speed Manual Optional Transmission Type: 4-Speed Automatic (optional) Features Clutch Type: Hydraulically operated single-plate dry clutch 📐 Dimensions Exterior Body Styles: 2-door Sedan, 4-door Sedan, Convertible, (Sport 'is' usually 2-door coupe) Wheelbase In: 101.2 inches Length In: 170.5 inches Width In: 66.5 inches Height In: 54.9 inches Weights Curb Weight Lbs Est: 2800 - 3000 lbs (depending on body style and options) 🛡️ Safety Features Ratings Crash Test Data: Limited official ratings from this era, but the E30 chassis was known for its robust build quality. Active Features Braking System: Front: Ventilated Disc Brakes; Rear: Solid Disc Brakes. ABS Availability: Optional on most models, standard on some late-production 'is' variants. Passive Features Seat Belts: 3-point inertia-reel seatbelts with front pre-tensioners (standard). Airbags: Not available on 1988 models. 💡 Technology Features Infotainment Audio System Features: Factory AM/FM cassette stereo system, often with optional premium sound (e.g., Nakamichi or Blaupunkt) and equalizer. Driver Assistance Cruise Control: Available as an option on many models. Connectivity Connectivity Features: Basic connectivity via antenna for radio; no modern Bluetooth or USB connectivity available in stock form. 🔧 Maintenance Service Intervals Oil Change Interval Miles: Typically every 5,000 - 7,500 miles or 6-12 months, depending on driving conditions. Refer to specific vehicle's owner's manual. Tune Up Interval: Spark plugs, air filter, fuel filter typically every 15,000 - 30,000 miles. This manual focuses on electrical, so these are general guidelines. Fluid Specifications Engine Oil Type: API SG, SAE 20W-50 or 15W-40 (check owner's manual for specific viscosity based on climate). Coolant Type: Ethylene glycol-based coolant, typically a 50/50 mix with distilled water. BMW Blue...