Case IH 518986-05 - BCM – BCM: BCM: Work lamp #6 - open circuit

The system has detected that the electrical circuit for Work Lamp #6 is incomplete. An "open circuit" typically means that electrical current cannot flow through the loop, which is most commonly caused by a blown bulb, a disconnected wiring harness, a broken wire, or a failed internal LED circuit.

• MAGNUM AFS Connect
• Magnum 400 AFS Connect

1. 1

   Visual Inspection: Check Work Lamp #6 for obvious physical damage, shattered lenses, or a disconnected plug.

2. 2

   Lamp Continuity Test: Disconnect the lamp and use a multimeter to test the lamp assembly for internal continuity. A blown halogen filament or a burnt-out LED board will read as an open circuit (infinite resistance).

3. 3

   Voltage and Ground Check: With the work lamp switch turned ON, check the machine-side connector for 12 volts and a solid ground.

4. 4

   Harness Inspection: If the lamp tests good but there is no voltage at the connector, inspect the wiring harness between the BCM and the lamp for chafing, broken wires, or pushed-out/corroded connector pins.

1. 1

   Power Down

   Turn off the ignition and disconnect the negative (-) battery cable to prevent electrical spikes during repair.

2. 2

   Disconnect the Lamp

   Locate Work Lamp #6 (refer to your specific operator's manual for the exact cab/fender position of lamp #6) and disconnect its electrical connector.

3. 3

   Inspect the Connector

   Check the terminals for corrosion, moisture ingress, or loose pins. Clean with contact cleaner if necessary.

4. 4

   Replace the Lamp (If Faulty)

   If the diagnostic continuity test proved the lamp has an internal open circuit, unbolt the faulty lamp assembly from its mounting bracket and install the replacement work lamp.

5. 5

   Repair the Harness (If Faulty)

   If the lamp is functional but the circuit is broken, trace the wiring back to the BCM. Splice and heat-shrink any broken wires, or replace the damaged connector pigtail.

6. 6

   Reassembly

   Plug the connector back into the work lamp and reconnect the negative battery cable.

7. 7

   Verify Repair

   Turn on the ignition and activate the work lamp switch. Verify that Work Lamp #6 illuminates and that the 518986-05 fault code clears from the AFS Pro display.