| Fuse # | Amperage | Circuit Protected | Common Failure Symptom | | :--- | :--- | :--- | :--- | | | 10A | Transmission Control Unit (TCU) | No gear indication / Tractor won't move | | F02 | 15A | Cigarette Lighter / Power Port | No 12V for chargers or GPS | | F03 | 10A | Left Headlight (Low/High) | Left light out | | F04 | 10A | Right Headlight | Right light out | | F05 | 15A | Windshield Wiper & Washer | Wiper motor dead | | F06 | 15A | Turn Signals & Hazard Flashers | No blinking / Flashers stuck on | | F07 | 5A | Instrument Cluster & Warning Lamps | Dead gauges / No dash lights | | F08 | 20A | Cab Interior Fan (HVAC) | Blower motor doesn't run | | F09 | 10A | Tail & Marker Lights (Running lights) | No rear lights | | F10 | 15A | Brake Lights & Reverse Lights | No brake lights (dangerous on road) | | F11 | 20A | Engine Control Unit (ECU) | Tractor dies / No start | | F12 | 30A | Fuel Lift Pump & Injection Pump shutoff | Engine cranks but won't start |
: To prevent damage to the tractor's electronics, never replace a blown fuse with one of a higher amperage rating. If a specific schematic is needed for deeper troubleshooting, the John Deere Service Manual TM4493 provides the complete high-resolution wiring harness maps. John Deere Are you experiencing a specific electrical failure fuse and wiring diagram for 6400 john deere tractor 2021
Connects the battery to the starter motor via the solenoid and neutral safety switch. If the tractor won't crank, check the neutral switch on the gear lever first. | Fuse # | Amperage | Circuit Protected