Case IH 520603-06 - BCM – BCM: Short circuit to ground on the circuit for Work Lamp #10

The voltage supply wire for Work Lamp #10 is making direct contact with a ground source before the current reaches the load, or the lamp assembly itself has suffered an internal short. This condition will typically cause the circuit's protective fuse to blow.

• MAGNUM AFS Connect
• Magnum 180 AFS Connect
• Magnum 200 AFS Connect
• Magnum 240 AFS Connect
• Magnum 340 AFS Connect
• Magnum 380 AFS Connect
• Magnum 400 AFS Connect

1. 1

   Check the Fuses: Locate the cab/lighting fuse box and check for a blown fuse associated with the work light circuits.

2. 2

   Isolate the Component: Identify the physical location of Work Lamp #10 and disconnect the electrical connector at the lamp.

3. 3

   Harness Continuity Test: With the battery disconnected and the lamp unplugged, use a digital multimeter set to Ohms (Ω) or continuity. Probe the power supply wire on the harness side and connect the other lead to a known good chassis ground. If you have continuity (low resistance), the wiring harness is shorted to ground.

4. 4

   Lamp Internal Short Test: If the harness tests fine (open circuit to ground), test the pins on the lamp assembly itself. A dead short across the lamp's internal circuitry means the light housing has failed.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the negative battery cable.

2. 2

   Address Harness Shorts

   If the multimeter test indicated a harness short, trace the wiring from Work Lamp #10 back toward the BCM. Carefully inspect pinch points, such as cab hinges, fender mounts, and areas where the harness routes tightly against the frame. Repair any chafed or melted wires using automotive-grade heat-shrink butt connectors and re-loom the wire.

3. 3

   Replace the Lamp

   If the diagnostic test proved the lamp itself is internally shorted, unbolt the defective Work Lamp #10 assembly from its bracket and install a replacement unit.

4. 4

   Replace the Fuse

   Replace the blown work light fuse in the fuse panel. Never use a fuse with a higher amperage rating than specified.

5. 5

   Test the System

   Reconnect the battery, turn on the ignition, and activate the work lights to verify the circuit holds and the light illuminates.

6. 6

   Clear Codes

   Use the tractor's AFS Pro display or a diagnostic scan tool to clear the 520603-06 fault code from the BCM memory.