John Deere 2398.06 – BLC (Basic Lighting Controller / Body Lighting Controller): Outer Worklights on Front of Roof, Current Too High

The Main Control Module (BLC) has detected abnormally high electrical current (amperage) in the circuit for the outer work light on the front of the cab roof. When the work lights are activated, the controller automatically shuts down the circuit to prevent damage to the wiring and components. This condition is typically caused by an incorrect high-wattage bulb, an internally shorted bulb, or a short circuit to ground in the wiring harness.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6MC Series
• 6RC Series
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC
• 6M Series
• 6R Series

1. 1

   Disconnect the front roof outer worklights at their pigtail connectors and turn on the switch to see if the code changes to an open circuit (isolating the short to the light assembly).

2. 2

   Inspect the halogen bulbs for internal shorting (melted filaments touching) and the light housings for water intrusion.

3. 3

   Perform a harness continuity test between the worklight power supply wire and a known good chassis ground to check for a short to earth.

4. 4

   Visually inspect the wiring harness from the roof down the cab pillars to the BLC module for pinch points, chafed insulation, or melted insulation.

5. 5

   Inspect the BLC module connector pins for signs of arcing, melting, or corrosion.

1. 1

   Disconnect battery

   Park the machine on a level surface, turn off the ignition, and disconnect the negative battery cable to ensure the circuit is dead.

2. 2

   Remove light assembly

   If the diagnostic checks isolated the issue to the light assembly, remove the retaining screws on the front roof outer worklights.

3. 3

   Replace bulb or assembly

   Replace the faulty bulb or the entire worklight assembly if the internal housing/reflector is melted or water-damaged.

4. 4

   Locate harness damage

   If the issue is in the wiring harness, locate the chafed or pinched section (commonly found near cab roof transition points).

5. 5

   Repair wiring harness

   Cut out the damaged section of the wire. Splice in a new section of appropriately gauged wire using marine-grade, adhesive-lined heat shrink butt connectors to ensure a waterproof seal.

6. 6

   Protect repaired harness

   Wrap the repaired harness section in protective split-loom tubing or high-temp electrical tape to prevent future chafing.

7. 7

   Clean and grease connectors

   Clean the BLC and worklight connectors with electrical contact cleaner. Apply a small amount of dielectric grease to the seals (not directly on the pins) to keep moisture out.

8. 8

   Reconnect battery

   Reconnect the battery.

9. 9

   Clear codes and test

   Turn the ignition on, clear the stored BLC fault codes using a diagnostic scan tool, and test the worklights to verify the high-amp code does not return.