1990 GMC R3500 Service and Repair Manual

1990 GMC R3500 service and repair manual — a detailed, factory-style reference for maintenance, diagnostics, and repair. Use it to confirm correct procedures, specifications, and system coverage before you start work.

Built for technicians and DIY owners, this manual helps you troubleshoot accurately, follow step-by-step repair procedures, and use wiring diagrams and system sections to diagnose problems faster.

What’s included

• Step-by-step repair procedures and service information
• Specifications and reference data (where provided)
• Electrical coverage with wiring diagrams
• Coverage across key systems: engine, transmission, brakes, steering, suspension, HVAC, and more

Trims covered

• SLE Cab & Chassis 4-Door
• SLE Crew Cab Pickup 4-Door
• Base Crew Cab Pickup 4-Door
• Base Cab & Chassis 4-Door

Engines covered

• 7.4L 454Cu. In. V8 GAS OHV Naturally Aspirated
• 6.2L 379Cu. In. V8 DIESEL OHV Naturally Aspirated
• 5.7L 350Cu. In. V8 GAS OHV Naturally Aspirated

Index / Table of contents

• Body
• Brakes
• Chassis Electrical
• Driveline
• Engine Cooling
• Engine Electrical
• Engine Mechanical
• Engine Performance & Emission Controls
• Fuel System
• General Information & Identification
• Heating, Ventilation, & Air Conditioning
• Hybrid & Electric Vehicle Systems
• Steering
• Suspension
• Transmission, Clutch, & Transfer Case
• Wiring Diagrams