John Deere 2396.03 – BLC (Basic Lighting Controller): Inner Worklights on Front of Roof, External Voltage

The system has detected voltage on the front roof inner worklight pin at the control module while the worklights are commanded OFF. This indicates an external voltage source is inappropriately applying power to the circuit, which is typically caused by a voltage back-feed or a short-to-power within the wiring loom.

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

1. 1

   Verify the Symptom: Turn off all worklights and use a multimeter to check for voltage at the front roof inner worklight connectors.

2. 2

   Isolate the Harness: Disconnect the front roof inner worklights from the roof wiring harness. Check if the voltage is still present on the BLC module's output pin.

3. 3

   Check for Shorts to Power: If voltage is still present at the BLC pin with the lights disconnected, inspect the wiring loom running from the BLC to the roof for chafing, melted insulation, or pinched wires that could be bridging the worklight circuit to a constant power source (short-to-power).

4. 4

   Inspect Connectors: Check the roof harness connectors for water intrusion, corrosion, or bent pins that could cause a bridge between a live circuit and the inner worklight circuit.

5. 5

   Test the BLC Module: If the wiring harness tests completely clear of shorts and back-feeds, the BLC module itself may have an internal fault leaking voltage to the pin.

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the negative battery terminal to prevent accidental shorts during repair.

2. 2

   Access the Wiring

   Remove the necessary cab roof panels or headliner sections to access the front inner worklight wiring harness and the routing down to the BLC module.

3. 3

   Repair or Replace the Harness

   If a short-to-power or chafed wire is found in the loom, cut out the damaged section and splice in new wire using weather-resistant heat-shrink butt connectors. If the harness is severely melted or damaged, replace the entire roof wiring harness.

4. 4

   Address Component Failures

   If the back-feed was caused by a short inside the worklight housing itself, replace the affected inner worklight assembly.

5. 5

   Reassemble and Clear Codes

   Reconnect all components, restore battery power, and turn the key to the ON position. Use a diagnostic tool to clear the BLC 002396.03 fault code.

6. 6

   Verify Operation

   Turn the worklights ON and OFF to ensure they operate correctly and that the fault code does not return.