Case IH 2386-06 - BCM – Body Control Module (BCM): Rotating Beacon Light Current above normal or grounded circuit

The control module has detected a short circuit to ground on the power supply circuit for the rotating beacon light. The voltage drops to zero or the current draw exceeds the maximum threshold because the power wire is touching a ground source before reaching the load, or the beacon light itself has an internal short.

• MAGNUM AFS Connect
• Magnum
• Steiger
• Puma
• Maxxum
• Optum
• Axial-Flow 7240
• Axial-Flow 8240
• Axial-Flow 9240

1. 1

   Check the cab fuse panel for a blown beacon light fuse, as a short to ground will almost always blow the circuit protection fuse.

2. 2

   Disconnect the rotating beacon light from its roof socket/connector to isolate the component.

3. 3

   Using a multimeter, measure the resistance across the power and ground pins on the beacon light itself (a reading near 0 ohms indicates an internal short).

4. 4

   With the beacon disconnected, use a multimeter to check for continuity between the power supply pin on the tractor-side harness and the cab ground to test for a harness short.

5. 5

   Inspect the wiring harness routing for signs of rodent damage or chafing against the metal frame, particularly where it passes through cab roof access panels, B-pillars, or near hinges.

1. 1

   Power Down

   Turn off the machine, remove the key, and locate the beacon light fuse in the cab fuse panel. If blown, remove it but do not install a new one yet.

2. 2

   Isolate the Fault

   Unplug the rotating beacon light from the cab roof bracket.

3. 3

   Test the Circuit

   Install a test fuse (or a load test light) in the fuse panel and turn the beacon switch ON. If the fuse blows immediately (or the test light illuminates brightly), the short is in the tractor's wiring harness; trace the wire from the roof connector down to the BCM/switch panel and repair any bare wires. If the fuse does NOT blow, the short is internal to the rotating beacon light assembly itself.

4. 4

   Replace the Component

   If the beacon is internally shorted, discard it and mount the replacement beacon to the DIN pole or flat mount.

5. 5

   Final Verification

   Reconnect the harness, install a new fuse of the correct amperage (typically 5A to 7.5A for halogen, 3A for LED), and turn on the beacon switch to verify proper operation and ensure the fault code clears from the display.