Case IH 520582-05 - BCM – BCM: Marker light front & rear right - open circuit

An open electrical circuit on the right side of the machine, meaning the electrical path to the front and rear right marker lights is broken. This is typically caused by a blown bulb, a failed LED assembly, a disconnected wiring harness, or a severed wire.

• MAGNUM AFS Connect
• Magnum 180
• Magnum 400 AFS Connect

1. 1

   Check the power source by verifying the battery for damage, state of charge, and ensuring connections are clean and tight

2. 2

   Inspect the main fuse and the cab fuse box for any blown fuses related to the lighting circuit

3. 3

   Visually inspect the right front and right rear marker lights for a burnt-out halogen bulb or a completely failed LED board

4. 4

   Use a multimeter to check for continuity in the wiring harness between the BCM and the right marker light connectors

5. 5

   Perform bypass testing using a fused jumper wire (equipped with a 5-amp fuse) to temporarily bypass suspected open segments of the circuit to isolate the break (Caution: Never connect a jumper wire across a short circuit)

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the battery to prevent electrical shorts during repair.

2. 2

   Access the Light Housings

   Remove the lenses or unbolt the right front cab/corner marker light and the right rear extremity marker light housings.

3. 3

   Replace Defective Lamps

   If the machine uses replaceable bulbs (e.g., #1156 12V bulbs), replace the blown bulb. If the machine is equipped with sealed LED assemblies, replace the entire right-hand LED marker light unit.

4. 4

   Inspect and Clean Connectors

   Disconnect the harness at the light fixtures. Inspect the pins for corrosion, moisture, or pushed-back terminals. Clean the contacts with electrical contact cleaner and reconnect securely.

5. 5

   Repair Wiring

   If the bulbs/LEDs are functional but the open circuit persists, trace the wiring harness back to the BCM. Locate the physical break or chafe in the wire and repair it using weather-sealed butt connectors or solder and heat shrink.

6. 6

   Test the System

   Reconnect the battery, turn the ignition ON, and activate the marker lights. Verify that the right front and rear marker lights illuminate and that the 520582-05 fault code clears from the AFS Connect display.