Case IH 520575-00 - BCM – BCM: Turn light front left - too many loads or faulty load

The control module has detected an excessive current draw on the front left turn signal circuit. This condition is typically caused by installing a bulb with too high a wattage, splicing aftermarket accessories into the turn signal circuit, or a faulty light assembly/wiring short drawing excessive amperage.

• MAGNUM AFS Connect
• Steiger AFS Connect

1. 1

   Verify if any aftermarket lights, flashers, or accessories have been spliced into the front left turn signal circuit (excessive load cause).

2. 2

   Inspect the front left turn signal bulb or LED assembly for internal faults, moisture intrusion, or shorts.

3. 3

   Trace the wiring harness leading to the front left turn signal (often routed near the LH A-Post) for pinched wires, chafing against the frame, or shorts to ground.

4. 4

   Ensure the BCM is fully powered down (sleep mode) and the battery isolator has clicked off before disconnecting BCM harnesses for pin-testing.

1. 1

   Power Down

   Turn off the ignition and wait for the BCM to enter sleep mode. Ensure the battery isolator has disconnected power to prevent electrical spikes during repair.

2. 2

   Remove Excess Loads

   If aftermarket lights were added to the front left turn signal circuit, remove them and wire them to an independent relayed circuit to restore the turn signal circuit to its factory load specification.

3. 3

   Replace Faulty Components

   If the wiring is intact but the fault persists, replace the front left turn signal assembly or bulb.

4. 4

   Repair Wiring/Connectors

   If chafed or shorted wiring is found, repair the damaged section. Replace any melted connector housings or corroded terminals at the LH A-Post connection.

5. 5

   Clear Codes

   Reconnect power, turn on the ignition, and use the electronic service tool (EST) to clear the BCM fault codes. Test the left turn signal to verify the repair.