Case IH 520550-06 - BCM – BCM: Left extended arm turn indicator - short circuit to ground

The control module has detected that the voltage on the output circuit supplying the left extended arm turn indicator lamp is being pulled directly to ground. This condition is typically caused by a pinched wire, chafed wire insulation touching the tractor's metal chassis, moisture intrusion in the connector, or an internal short circuit within the lamp assembly itself.

• MAGNUM AFS Connect
• Magnum 180 AFS Connect
• Magnum 200 AFS Connect
• Magnum 220 AFS Connect
• Magnum 240 AFS Connect
• Magnum 250 AFS Connect
• Magnum 280 AFS Connect
• Magnum 310 AFS Connect
• Magnum 340 AFS Connect
• Magnum 380 AFS Connect
• Magnum 400 AFS Connect

1. 1

   Visually inspect the wiring harness running along the left extended arm to the turn indicator lamp for chafing, pinched wires, or exposed copper touching the frame.

2. 2

   Disconnect the left extended arm turn indicator lamp and inspect the mating connector (X-238) for dirt, rust, moisture, or melted pins.

3. 3

   Isolate the short: With the lamp unplugged and ignition ON, activate the left turn signal. If the code changes to 'open circuit', the short is internal to the lamp. If it persists, the short is in the harness.

4. 4

   Perform a harness continuity test: Turn off ignition, unplug the BCM connector, and use a multimeter to check for continuity between the turn indicator output pin and chassis ground.

5. 5

   Check BCM supply fuses (F-003, F-004, F-005, F-006) in the cab fuse and relay panel to verify they are intact.

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the battery to prevent accidental electrical spikes during repair.

2. 2

   Access the Harness

   If the diagnostic tests pointed to a wiring issue, trace the harness from the left extended arm down into the cab routing.

3. 3

   Repair the Wiring

   Once the chafed or pinched section of the wire is located, cut out the damaged section. Splice in a new section of wire using automotive-grade solder and weather-sealed heat shrink tubing. Wrap the repaired section in protective loom.

4. 4

   Replace the Lamp

   If the diagnostic tests proved the lamp was internally shorted, unbolt the left extended arm turn indicator housing and install a replacement unit.

5. 5

   Replace Connectors

   If the connector is melted or heavily corroded, cut it off and pin a new 2-cavity male connector (Part # 87696547).

6. 6

   Reassemble and Test

   Reconnect the battery. Turn the ignition ON and activate the left turn signal. Verify the light flashes correctly and use the AFS Pro display to confirm the 520550-06 fault code has moved to an 'inactive' state or can be cleared.