Case IH 520602-05 - BCM – BCM: Work lamp #2 - open circuit (Current Below Normal or Open Circuit)

The controller is attempting to send power to the "Work Lamp #2" circuit, but it detects zero or abnormally low current draw. This indicates an incomplete electrical path, which is almost always caused by a burnt-out bulb, a failed LED assembly, a disconnected plug, or a broken wire in the harness.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect Series
• Steiger AFS Connect

1. 1

   Identify the exact physical light corresponding to 'Work Lamp #2' using the Pro 1200 display or the operator's manual.

2. 2

   Visually inspect the lamp for physical damage, water intrusion, or a visibly burnt-out halogen filament.

3. 3

   Disconnect the wiring harness at the lamp and inspect the pins for corrosion, moisture, or pushed-out terminals.

4. 4

   With the tractor running (or key ON) and the work lamp switch activated, use a multimeter to check for 12V at the harness connector.

5. 5

   Check the ground pin on the harness connector for continuity to the chassis ground. Result A: If you have 12V and a good ground at the connector, the lamp assembly itself has failed (internal open circuit) and must be replaced. Result B: If you do not have 12V, the open circuit is in the wiring harness between the BCM and the lamp.

1. 1

   Disconnect battery

   [If the lamp assembly has failed] Turn off the tractor ignition and disconnect the negative battery cable to prevent short circuits.

2. 2

   Unplug connector

   Unplug the electrical connector from the back of Work Lamp #2.

3. 3

   Remove mounting hardware

   Remove the mounting nut/bolt securing the lamp bracket to the cab or fender.

4. 4

   Mount new lamp

   Mount the new work lamp assembly and tighten the hardware.

5. 5

   Apply dielectric grease and connect

   Apply a small amount of dielectric grease to the connector pins (if recommended by the OEM) and plug the harness into the new lamp.

6. 6

   Reconnect battery and test

   Reconnect the battery, turn the key ON, and test the work lamp switch.

7. 7

   Clear fault code

   Clear the inactive fault code from the BCM using the Pro 1200 display or an electronic service tool.

8. 8

   Trace wiring harness

   [If the wiring harness is broken] Trace the wiring harness from the lamp back toward the cab roof/BCM.

9. 9

   Inspect for damage

   Look for pinch points, areas where the loom has rubbed against the frame, or damaged inline connectors.

10. 10

    Repair open circuit

    Once the break is found, strip the wire back, use an environmentally sealed (heat-shrink) butt connector to repair the open circuit, and re-loom the wire.