Case IH 520582-00 - BCM – BCM: Left rear turn light - open circuit

The BCM detects no electrical load on the left rear turn signal circuit (open circuit), typically caused by a burnt-out bulb, disconnected harness, or broken wire. Note: The dossier also addresses code 520561-00 (Marker light front & rear right - too many loads or faulty load) caused by excessive current draw or short to ground.

• MAGNUM AFS Connect
• Magnum series tractors
• Magnum 180-400
• MX Series Magnums

1. 1

   Verify the exact code: 520561-00 (Right Marker Lights) or 520582-00 (Left Rear Turn Light)

2. 2

   Inspect the affected light housings for blown bulb filaments (open circuit) or incorrect wattage bulbs (too many loads)

3. 3

   Inspect the wiring harness for pinched wires, chafed insulation causing a short to ground, or stretched wires causing an open circuit

4. 4

   Disconnect the pigtail at the light assembly and check for green corrosion, water ingress, or melted plastic inside connector pins

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent further electrical shorts or damage to the BCM.

2. 2

   Access the Assembly

   Remove the retaining screws for the lens or the entire light housing of the affected light (Right Marker or Left Rear Tail Light).

3. 3

   Bulb & Socket Replacement

   Remove the bulb. If it is burnt out, replace it with the exact OEM-specified wattage bulb. If the socket is melted or heavily corroded, the entire light assembly or pigtail must be replaced.

4. 4

   Wiring Repair

   If the bulb and socket are fine, trace the wiring harness back toward the BCM. If you find a chafed wire shorting to the frame (causing the 'too many loads' code) or a broken wire (causing the 'open circuit' code), cut out the damaged section. Splice in a new section of wire using marine-grade heat-shrink butt connectors to ensure a weather-tight seal.

5. 5

   Remove Aftermarket Splices

   If any aftermarket monitors or accessories are tapped into the marker light circuit, remove them and wire them to an independent fused power source.

6. 6

   Test

   Reconnect the battery, clear the inactive fault codes from the BCM, and turn on the lights/turn signals to verify the repair.