Caterpillar 938H and IT38H Wheel Loader Electrical System Wiring Schematic

This wiring reference for the Caterpillar 938H and IT38H Wheel Loader Electrical System Wiring Schematic helps you follow circuits, connectors and harnesses when you are diagnosing an electrical problem or checking a repair.

Document reference: RENR9764-06.

What the diagrams cover

• Complete component location tables (engine/chassis and cab) with schematic grid references
• Connector location charts
• Component Identifier (CID), Module Identifier (MID), and Failure Mode Identifier (FMI) diagnostic code tables for Engine Control (MID 036), Payload Control (MID 074), Electronic Transmission Control (MID 081), and Electronic Implement Control (MID 082)
• Full wire-by-wire circuit descriptions with wire numbers, colors, and gauges
• Complete wire-level schematic diagrams for engine, chassis, and cab harnesses
• Off-machine switch specifications and resistor/sender/solenoid specifications
• Related electrical service manual cross-reference table

Models covered

• 938H
• IT38H Wheel Loader

User help

1. Make sure it matches your machine. Look up your model and serial number and compare them with the coverage above. Not sure? Send us those details and we will help you check before you buy.
2. Get the file. This is a digital PDF download. Nothing is shipped, so you can start using it as soon as you have the file.
3. Open it anywhere. Use any current PDF reader (Adobe Acrobat Reader, your browser, or a phone or tablet app). Save a copy to your computer and to a backup drive.
4. Jump straight to the section you need. Start from the table of contents or search for a part name, fault code or value, then print just those pages for the workshop.
5. Trace circuits methodically. Identify the circuit, connector or harness in the diagram, then check voltage, continuity and grounds at the points shown before replacing components.
6. Stay safe. Repairs on engines, hydraulics, fuel and electrical systems can be dangerous. Follow the safety instructions in the document, use proper tools and support equipment, and follow local regulations.

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