The wiring diagram for a 2021 John Deere 6400 tractor is complex and consists of multiple pages. However, here is a simplified overview of the main components and their connections:
Comprehensive Guide: Fuse and Wiring Diagram for 6400 John Deere Tractor (1994-2021 Troubleshooting) fuse and wiring diagram for 6400 john deere tractor 2021