Case IH 520600-00 - BCM – Body Control Module (BCM): Work lamp #1 - too many loads or faulty load

Circuit is drawing excessive current (overload), likely due to a short circuit to ground, a short circuit to the battery, or a defective component on the Work Lamp #1 circuit.

• MAGNUM AFS Connect
• Case IH Magnum (225, 250, 280, 310, 235-340 Series 4)
• Case IH Maxxum (EP 110-140)

1. 1

   Check if the code is an Active or Permanent fault (Active faults will often disable the lighting circuit immediately to protect the BCM)

2. 2

   Unplug Work Lamp #1 to isolate the load; if the circuit overload stops, the fault is isolated to the lamp housing or bulb

3. 3

   Inspect the light switch and test the terminals with a multimeter, as a worn switch is a common cause of lighting failures

4. 4

   Inspect the lighting harness (specifically the left/right hand work lamp connectors) for rubbed wires causing a short to ground or short to battery

5. 5

   Test the Work Lamp Relay (e.g., Cavity A) and check associated chassis ground connections

1. 1

   Disconnect Power

   Always disconnect the battery before performing electrical repairs to prevent further damage to the BCM.

2. 2

   Replace the Faulty Component

   If the diagnostic checks point to the switch, replace the tractor light switch. If the wiring harness is damaged, repair the broken/shorted wires in the lighting harness and ensure clean chassis grounds. If the lamp itself is internally shorted (drawing too many loads), replace the work lamp assembly.

3. 3

   BCM Repair (If Applicable)

   If the circuit overload has permanently damaged the Body Control Module, the BCM will need to be removed and sent to a specialized ECU/BCM repair service, or replaced entirely.

4. 4

   Clear the Code

   Once the physical repair is complete, reconnect the battery and use a diagnostic tool (or perform a cycle test) to clear the fault code from the ECU memory.