John Deere 2360.03 – BLC (Basic Lighting Controller / Light Control Unit): Circuit short to power or External Voltage on the rear work light circuit

The controller is detecting voltage on the rear mud guard/fender work light pin when the lights are commanded off, confirming a voltage backfeed in the wiring loom.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6M Series
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC
• 310SK
• 315SK
• 410K

1. 1

   Check the Vehicle Control Unit (VCU) Circuit: Ensure there are no communication errors or power supply issues stemming from the VCU.

2. 2

   Check the Start and Charge Circuit: Verify that the alternator and battery are providing the correct system voltage without spikes.

3. 3

   Check the Controller Area Network (CAN) Circuit: Ensure the BLC is communicating properly with the rest of the machine's modules.

4. 4

   Inspect Circuits E1 and E4: Specifically test the left rear work light (E1) and right rear work light (E4) circuits for a short to battery voltage.

1. 1

   Disconnect electrical power

   Disconnect the battery negative cable to prevent accidental shorts or battery explosions during electrical testing.

2. 2

   Access the Wiring Loom

   Locate the wiring harness leading to the rear mud guard / fender work lights.

3. 3

   Inspect for Damage

   Visually inspect the loom for chafed wires, melted insulation, or pinch points where the work light power wire may be rubbing against a constant hot wire, causing the voltage backfeed.

4. 4

   Test the Harness

   Disconnect the harness at the BLC module and at the rear work lights. Use a multimeter to check for continuity to power on the work light pins.

5. 5

   Repair Wiring

   If a short to power is found in the harness, repair the damaged section of the wiring loom or replace the harness.

6. 6

   Check the BLC Module

   If the wiring loom tests perfectly fine with no external voltage present when disconnected, the BLC module itself may have an internal fault (internal short to power) and will require replacement or a software re-flash.