Case IH 520582-06 - BCM – BCM: Marker light front & rear right - short to B+

Circuit fault in the Marker light front & rear right indicating a short to B+ (short to battery positive), which is a dead short in the right-side marker light circuit that is drawing excessive current or receiving improper voltage.

• MAGNUM AFS Connect
• Magnum AFS Connect series (Models 180, 200, 220, 240, 250, 280, 310, 340, 380, 400)
• Steiger AFS Connect series
• Puma series (Models 200, 215, 230)

1. 1

   Inspect the right front and right rear marker light assemblies for cracked lenses, water ingress, or melted bulb sockets.

2. 2

   Trace the right-side marker light wiring harness for pinch points, chafed insulation rubbing against the tractor frame, or damaged connectors.

3. 3

   Disconnect the right marker light connectors. Use a multimeter to check for continuity to ground (if testing for a short to ground) or check for unexpected 12V voltage on the signal wire (if testing for a short to B+) when the lighting circuit is turned off.

4. 4

   Inspect the main harness connectors at the Body Control Module (BCM) for pushed-out pins, corrosion, or moisture.

1. 1

   Disconnect Power

   Always disconnect the battery negative cable before servicing BCM-controlled electrical circuits to prevent accidental module damage.

2. 2

   Isolate the Short

   Disconnect both the front right and rear right marker lights. Reconnect the battery and test the circuit. If the fault code changes to an "open circuit" (e.g., 520581-06), the short is internal to one of the light housings. If the short circuit code remains, the fault is in the wiring harness between the BCM and the lights.

3. 3

   Repair the Wiring/Component

   If a light housing is internally shorted, replace the entire marker light assembly. If the harness is chafed, cut out the damaged section of wire, splice in a new section using weather-resistant heat-shrink butt connectors, and re-loom the harness.

4. 4

   Reassemble and Clear Codes

   Reconnect all light assemblies. Turn the tractor key to the ON position, enter the diagnostic menu on the AFS Pro display, and clear the inactive BCM fault codes.

5. 5

   Verify Operation

   Turn on the marker lights (often requires the tractor to be in ROAD mode for full diagnostic monitoring) and verify the lights illuminate without triggering the code.