This comprehensive wiring diagram manual provides detailed instructions for diagnosing and resolving electrical issues in your 1991 Porsche 928 S4-GT (Model 91). It offers the same technical information used by professional garages and workshops, allowing you to save money by tackling electrical repairs yourself. The manual includes detailed illustrations and diagrams, making it easy to understand and follow, even if you have limited electrical knowledge. With its clear explanations and visual aids, this manual empowers you to safely and confidently repair your car's electrical system.

The Porsche 928 S4-GT, a limited-edition variant of the iconic 928 grand tourer, was a true testament to Porsche's engineering prowess and commitment to performance. Introduced in 1989, the S4-GT was a homologation special designed to meet the requirements of the Group A racing category. Only 250 units were produced, making it a highly sought-after collector's item today. The S4-GT was built on the foundation of the already powerful 928 S4, boasting a 5.0-liter V8 engine producing 320 horsepower. This engine, coupled with the car's lightweight construction, resulted in a blistering 0-60 mph time of just 5.2 seconds and a top speed exceeding 160 mph. The S4-GT was further distinguished by a series of aerodynamic and performance enhancements. A more aggressive front bumper with a larger spoiler, a rear wing with a prominent Gurney flap, and a unique rear diffuser were all designed to improve downforce and stability at high speeds. Inside, the interior was stripped down to focus on performance, with lightweight Recaro seats, a simplified dashboard, and a racing-inspired steering wheel. The S4-GT's significance transcends its performance figures. It represents a pivotal moment in Porsche's history, showcasing the brand's commitment to pushing the boundaries of both road and track performance. While the 928 was initially seen as a successor to the 911, the S4-GT firmly cemented its place as a formidable grand tourer in its own right, capable of delivering both thrilling performance and exceptional comfort.