Case IH 520601-06 - BCM – BCM: Short circuit to ground on Work Lamp #4 circuit

Fault code 520601-06 indicates a short circuit to ground on the circuit supplying power to Work Lamp #4. The voltage intended to power the work lamp is finding a direct path to the chassis ground before passing through the load, causing the control module to disable the circuit to protect the wiring harness.

• MAGNUM AFS Connect
• Case IH Magnum Series
• Case IH Steiger Series
• Case IH Puma & Optum Series
• Case IH Axial-Flow Combines

1. 1

   Visual Inspection of the Lamp: Inspect Work Lamp #4 for physical damage, water ingress, or a shattered housing.

2. 2

   Connector Check: Disconnect the lamp and inspect the electrical connector for melted plastic, burnt pins, or heavy corrosion.

3. 3

   Harness Isolation Test: With the lamp disconnected and the battery disconnected, use a digital multimeter set to Ohms (Ω) to probe the power supply wire in the harness connector and the other lead to a known good chassis ground. Continuity indicates a harness short; no continuity indicates an internal lamp short.

4. 4

   Harness Routing Inspection: If the harness is shorted, visually trace the wire back to the BCM, paying close attention to pinch points such as cab pillars, roof panels, or near hinges.

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the negative battery cable to prevent accidental electrical spikes.

2. 2

   Isolate the Fault

   Disconnect Work Lamp #4.

3. 3

   Repair the Harness (If applicable)

   If the multimeter test showed a short in the harness, locate the chafed or pinched section of the wire. Cut out the damaged section, strip the ends, and splice in a new section of wire of the same gauge using weather-resistant crimp connectors and adhesive-lined heat shrink tubing.

4. 4

   Replace the Lamp (If applicable)

   If the harness tests good, the lamp has an internal short. Unbolt the mounting bracket, remove the faulty lamp, and install the replacement unit.

5. 5

   Reassemble and Test

   Reconnect the work lamp and the battery. Turn on the ignition and activate the work lights. Verify that Work Lamp #4 illuminates and that the BCM no longer logs the 520601-06 active fault code. Clear any stored inactive codes via the AFS Pro monitor or diagnostic tool.