Case IH 520575-06 - BCM – BCM: Left side turn light - short circuit to ground

The controller has detected that the voltage on the circuit supplying the front left turn signal is dropping to zero, indicating that the power wire is making direct contact with the chassis ground or there is an internal short within the light assembly itself.

• MAGNUM AFS Connect
• Magnum 400 AFS Connect

1. 1

   Inspect the front left turn signal housing for physical damage, water ingress, or condensation, which can cause internal shorts.

2. 2

   Trace the wiring harness from the front left turn signal back toward the BCM. Look for pinched wires, chafing against the tractor frame, or melted insulation.

3. 3

   Disconnect the plug at the front left turn signal. Inspect the pins for corrosion, bridging, or moisture.

4. 4

   With the light disconnected, use a digital multimeter to measure continuity between the power wire on the harness side and a known good chassis ground. Continuity indicates a harness short; no continuity indicates an internal short in the light assembly.

1. 1

   Power Down

   Turn off the ignition and disconnect the negative battery cable to prevent accidental spikes during repair.

2. 2

   Isolate the Fault

   Based on the multimeter testing above, determine if the fault is in the harness or the light assembly.

3. 3

   Repair the Harness (If Applicable)

   If the wire is chafed and shorting to the frame, cut out the damaged section, solder in a new piece of wire of the same gauge, and seal it with marine-grade heat shrink. Secure the harness with zip ties away from sharp edges.

4. 4

   Replace the Light Assembly (If Applicable)

   If the short is internal to the light, unbolt the front left turn signal housing from the cab/fender mount, disconnect the pigtail, and install the replacement unit.

5. 5

   Reassemble and Test

   Reconnect the battery, turn the key to the ON position, and activate the left turn signal. Verify that the light flashes normally and the dash indicator functions without hyper-flashing.

6. 6

   Clear Codes

   Use the AFS Pro display or the Case IH Electronic Service Tool (EST) to clear the inactive 520575-06 code from the BCM memory.