John Deere 002354.03 – BLC: Voltage Detected on Work Light Pin When Lights Are Off

The Main Control Module (BLC) has detected voltage on the bonnet corner work light circuit when the lights are switched off. This condition is typically caused by a voltage backfeed within the wiring loom, where voltage from another active circuit unintentionally bleeds into the work light circuit due to harness damage, moisture, or shared connector issues.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M

1. 1

   Visually inspect the wiring harness related to the bonnet/hood corner work lights for chafing, pinched wires, or corrosion on connectors

2. 2

   Inspect connectors for moisture ingress, which can create unintended electrical pathways

3. 3

   Disconnect the affected work light to see if the code disappears, which isolates whether the issue is internal to the light assembly

4. 4

   Using a multimeter set to DC volts, probe the work light pin at the BLC connector with the lights switched off to confirm the presence of stray voltage

5. 5

   Trace the harness to identify the source of the backfeed by disconnecting other circuits one by one until the stray voltage disappears

6. 6

   Check the main chassis and cab ground connections for tightness and corrosion, as a poor ground on a related circuit can cause current to find an alternative path

1. 1

   Repair wiring harness

   If a specific location of chafing or a short between wires is identified, carefully separate the affected wires, repair any breaks in the insulation, and ensure they are no longer in contact.

2. 2

   Replace damaged connectors

   If any connector is found to be corroded or damaged by moisture, replace the connector to eliminate the unintended electrical pathway.

3. 3

   Replace wiring harness

   If the wiring loom is extensively damaged and cannot be reliably repaired, replace the entire affected harness section.

4. 4

   Clear fault codes

   After repairs are complete, clear the fault codes from the BLC and operate the lights to ensure the fault does not return.