Case IH 520587-00 - BCM – BCM: Trailer right turn indicator - too many loads or faulty load

Indicates an overcurrent condition or a short circuit on the trailer's right turn signal circuit. The control module monitors the electrical current (amperage) going to the trailer plug. If the current draw exceeds the maximum threshold, it logs this code.

• MAGNUM AFS Connect

1. 1

   Isolate the Tractor from the Trailer: Disconnect the implement/trailer plug from the tractor's 7-pin receptacle. Clear the fault codes and activate the right turn signal.

2. 2

   Inspect the Receptacle: Check the tractor's 7-pin trailer socket for heavy corrosion, moisture, dirt, or bent pins bridging the right turn signal pin to a ground pin.

3. 3

   Check Trailer Load: If the fault is on the trailer, verify how many lights are on the right turn circuit. Ensure no incorrect, high-wattage bulbs were recently installed.

4. 4

   Circuit Testing: Use a digital multimeter to test the right turn signal wire between the BCM and the rear trailer socket for continuity to ground (indicating a chafed/shorted wire).

1. 1

   Clean and Inspect Connections

   If the 7-pin trailer socket is corroded or packed with conductive debris, thoroughly clean it with electrical contact cleaner and a terminal brush. Apply dielectric grease.

2. 2

   Repair Tractor Wiring

   If the multimeter test shows a short to ground on the tractor side, trace the wiring harness from the rear socket forward to the BCM. Look for pinch points near the cab mounts or rear fenders. Splice and heat-shrink any damaged wires.

3. 3

   Repair Trailer Wiring

   If the tractor tests fine, inspect the implement's wiring harness. Repair any exposed wires touching the trailer chassis.

4. 4

   Reduce Circuit Load

   If the trailer has an excessive number of incandescent marker/turn bulbs, convert the trailer lighting to LEDs to drastically reduce the amperage draw and prevent the BCM from tripping the 'too many loads' fault.

5. 5

   Clear and Verify

   Reconnect the trailer, turn on the tractor, clear the BCM fault codes, and activate the right turn signal to verify the repair.