The 1988 Porsche 928 S is a distinguished 2+2 coupe, representing Porsche's foray into the luxury grand tourer segment. Engineered with a front-engine, rear-wheel-drive layout and a sophisticated transaxle design for optimal weight distribution, this model embodies a blend of performance and comfort. Its powerful V8 engine, displacing 5.0 liters and producing approximately 288-306 horsepower, was a significant departure from Porsche's traditional rear-engine sports cars. The 928 S was designed to compete with established luxury GTs, offering advanced technology and a high level of refinement for its era, and was recognized with awards such as Motor Trend's Car of the Year in 1978 for its innovative approach.

This manual is a comprehensive guide focused on the Electrical System Troubleshooting and Repair of the 1988 Porsche 928 S. It provides detailed coverage of wiring diagrams, component identification, and electrical fault diagnosis, essential for maintaining the vehicle's complex systems. The manual includes step-by-step diagnostic procedures, guidance on component testing, wiring harness tracing, and fuse/relay identification, along with connector pinouts. Designed for professional technicians and knowledgeable enthusiasts, it assumes a foundational understanding of automotive electrical principles and diagnostic tools, empowering users to effectively diagnose and repair electrical issues within the engine management, lighting, instrumentation, comfort, and safety systems.