Case IH 518985-05 - BCM – BCM: Work lamp #7 - open circuit

The control module is attempting to send power to Work Lamp #7, but it detects zero current draw. This "open circuit" condition typically means the circuit is physically broken. Common causes include a burnt-out bulb/failed LED, a disconnected plug, a severed wire, or severe corrosion in the connector preventing electrical contact.

• MAGNUM AFS Connect
• Magnum 380
• Magnum 400 AFS Connect

1. 1

   Identify the Lamp: Consult the operator's manual to locate the specific physical position of "Work Lamp #7" (work lamps are typically located on the front hood, mid-mount cab, rear fenders, or upper cab roof).

2. 2

   Visual Inspection: Inspect the lamp housing for physical damage or water intrusion.

3. 3

   Connector Check: Unplug the connector at Work Lamp #7. Inspect the pins for pushed-out terminals, green corrosion, or moisture.

4. 4

   Component Test: Apply a direct 12V power and ground source to the lamp's pins. If the lamp does not illuminate, the lamp itself has failed.

5. 5

   Circuit/Continuity Test: If the lamp works, use a multimeter to check for continuity on the power wire between the BCM output and the lamp connector. Check the ground wire for high resistance to the chassis ground.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery ground to prevent accidental short circuits during repair.

2. 2

   Access the Lamp

   Safely access Work Lamp #7. If it is a cab-mounted light, use proper steps/ladders.

3. 3

   Disconnect and Remove

   Unplug the wiring harness connector from the back of the work lamp. Unbolt the mounting bracket hardware securing the lamp to the tractor.

4. 4

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a broken wire or corroded connector, splice in a new section of wire or replace the pigtail connector using weather-sealed heat-shrink butt connectors.

5. 5

   Replace the Lamp (If Applicable)

   If the lamp failed the direct-power test, mount the new OEM replacement lamp to the bracket and tighten the hardware.

6. 6

   Reconnect and Test

   Plug the wiring harness back into the lamp. Reconnect the tractor's battery.

7. 7

   Clear Codes

   Turn the key on, activate the work lights via the AFS Connect display or armrest controls, and verify the light illuminates. Clear the inactive 518985-05 fault code from the BCM memory.