1987 Chevrolet Corvette Alternator Delco Repair Manual (P/N 25063)

This 100-page official General Motors publication (P/N 250631987) serves as the definitive testing and overhaul reference for the 1987 Chevrolet Corvette charging system. It details the complete Delcotron line, carefully differentiating between the SI and CS internal regulator architectures.

Component and Diagnostic Documentation

The manual breaks down operational theory and bench testing procedures for both SI and CS series units. Coverage begins with visual inspection routines—checking belt tension and terminal integrity. From there, it transitions to on-vehicle charging tests using standardized diagnostic equipment. Workshop professionals will find exact guidance for tracking down open circuits. You will also see how to rectify undercharged or overcharged battery conditions and verify voltage regulator settings. When dealing with high-amperage electrical systems, always disconnect the battery negative cable first to prevent accidental shorts or component damage.

Internal component testing procedures cover stators, rotors, rectifier bridges, and diode trios. Need electrical reference data? The text provides exact ohms-based rotor winding checks and diode function analysis. It also reviews the mechanical side. You get a clear look at bearing replacement, slip ring servicing, field winding verification, and correct mounting bolt torque values. Additionally, an extensive section maps out electrical component locations throughout the vehicle, including relays, sensors, and fuse blocks.

Specification Highlights

You get comprehensive test specifications for the entire Delco-Remy lineup. Data regarding 10SI through 27SI, along with CS-121 and CS-130 series performance, is clearly tabulated. This makes quick reference during a complex troubleshooting session much easier.

• Detailed coverage of Delco-Remy 10SI, 12SI, 15SI, 17SI, 27SI, CS-121, and CS-130 alternator variants.
• 15 diagnostic figures, featuring a 10SI cutaway view, SI series terminal identification, wiring schematics, and bench connection diagrams.
• Rotor resistance for SI series units specified at 2.4 to 3.5 ohms.
• Rated outputs for the 1987 Corvette alternator lineup ranging from 37 to 108 amps.
• Regulator voltage test settings documented at a minimum of 13.5 volts and a maximum of 16.0 volts.