1987 Porsche Service Training Manual Electric

The 1987 Porsche Service Training Manual Electric provides comprehensive technical information and service procedures for Porsche electric systems from the 1987 model year. This manual covers electrical theory, diagnostic procedures, repair techniques, and maintenance protocols for Porsche vehicles including the 911, 928, 944, and 924 models. Below are key sections covering electrical systems, components, troubleshooting, and service procedures.

Electrical System Overview

Porsche 1987 models feature advanced 12-volt negative ground electrical systems with comprehensive electronic monitoring and control systems.

Battery and Charging System

Maintenance and service procedures for battery, alternator, and voltage regulation systems.

1. Battery Testing: Perform specific gravity test and load test procedures.
2. Alternator Service: Check belt tension, output voltage, and rectifier diodes.
3. Voltage Regulator: Test regulator function and replace if output exceeds 14.8V.
4. Charging Circuit: Inspect wiring harness for corrosion and proper connections.

WARNING! Disconnect battery negative terminal before performing electrical work to prevent short circuits and injury.

Starting System

Diagnosis and repair of starter motor, solenoid, and ignition switch circuits.

1. Starter Motor Test: Check current draw and cranking RPM specifications.
2. Solenoid Function: Test solenoid engagement and pinion gear operation.
3. Ignition Switch: Verify proper voltage at starter trigger wire during cranking.
4. Starter Relay: Test relay function and replace if contacts are worn.

CAUTION! Ensure transmission is in Park or Neutral before testing starter system to prevent accidental vehicle movement.

Lighting Systems

• Headlight System: Sealed beam or H4 halogen depending on model and market.
• Turn Signals: Electronic flasher unit with bulb-out warning.
• Brake Lights: Dual filament bulbs with third brake light on later models.
• Interior Lighting: Dome lights with door switch activation.
• Fog Lights: Optional auxiliary lighting with separate switch.
• Lighting Controls: Multi-function stalk with dimmer function.
• Bulb Types: Various European standard bulb specifications.
• Circuit Protection: Individual fuse protection for lighting circuits.

Instrument Cluster and Gauges

Service procedures for speedometer, tachometer, fuel gauge, temperature gauge, and warning lights.

Instrument Cluster: Analog gauges with electronic sending units. Warning lights include oil pressure, alternator, brake system, and check engine.

Speedometer: Cable-driven or electronic VDO unit. Tachometer: Electronic with signal from ignition system. Fuel Gauge: Float-type sending unit in fuel tank. Temperature Gauge: Thermal sensor in cylinder head. Oil Pressure Gauge: Mechanical or electrical sending unit. Warning Light Testing: Bulb check during ignition-on position.

Power Windows and Locks

Troubleshooting and repair of power accessory systems.

1. Window Motor Test: Check current draw and operation in both directions.
2. Regulator Mechanism: Inspect for binding or worn components.
3. Switch Testing: Verify voltage at switch terminals during operation.
4. Lock Actuators: Test solenoid operation and linkage movement.

Tip: Lubricate window channels with silicone spray to reduce motor load.

Climate Control Systems

Electrical components of heating, ventilation, and air conditioning systems.

1. Blower Motor: Test speed control and resistor pack function.
2. AC Compressor: Check clutch engagement and cycling switch.
3. Temperature Control: Test blend door actuators and control head.
4. Ventilation: Verify operation of mode door motors and switches.
5. Defroster System: Check rear window defogger grid and timer relay.
6. Control Panel: Diagnose electronic climate control modules.
7. Sensor Testing: Check ambient and interior temperature sensors.
8. Relay Operation: Test HVAC system relays for proper function.

WARNING! Disconnect battery before servicing airbag-equipped models to prevent accidental deployment.

Engine Management Electronics

Digital Motor Electronics (DME) system diagnosis and service.

Closed Captions: Enable in DVD setup (On/Off). Parental Controls: Block by movie/TV ratings in FEATURES menu (password 9999).

Wiring Diagrams

Reference diagrams for all electrical circuits with color codes and connector locations.

CAUTION! Use only factory wiring diagrams for accurate circuit tracing and repair.

Diagnostic Procedures

Systematic approach to electrical problem diagnosis using factory tools and procedures.

Porsche specific diagnostic equipment required for advanced system troubleshooting. Basic electrical tests can be performed with standard multimeter. Follow systematic diagnostic trees for efficient problem solving. Document all test results and measurements. Verify repairs with operational testing.

Troubleshooting Guide

Reset: Disconnect battery for 10 minutes to reset electronic modules.

Service: Refer to Porsche dealer for specialized diagnostic equipment and programming.