John Deere 2386.05 – RLC or BCU: Beacon Light, Current Too Low

The control software registers that the current at the output to the beacon light is too low (less than 500 mA) despite the light being switched on, indicating an open circuit condition.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6000 Series
• 6110
• 6230
• 6330
• 6430
• 8R/RW Series
• 8245R
• 8400R
• 9RT Series
• 9470RT
• 9520RT
• 9570RT
• 250D
• 300D Series II
• 260E
• 310E
• XCG 330LC-8B

1. 1

   Visual Bulb Check: Visually inspect the beacon light bulb to see if it is blown.

2. 2

   Inspect Wiring and Connectors: Carefully examine the beacon light and its associated wiring for any signs of disconnection, damage, or wear that could result in an open circuit.

3. 3

   Continuity and Voltage Test: Ensure that all connectors and wiring specifically leading to and from the beacon light are secure and intact. Use a multimeter to test the continuity of the beacon light circuit from the power module (RLC or BCU) to the light itself.

1. 1

   Cycle Power

   Cycle the key switch or tractor power to clear potential transient voltage drops.

2. 2

   Replace the Bulb

   If the bulb is blown, replace it with the correct wattage bulb.

3. 3

   Repair Wiring

   If a disconnection or break in the circuit is identified during the continuity test, repair the wiring harness or replace the damaged connector pins to restore proper function.

4. 4

   Replace the Beacon Assembly

   If the wiring is intact and power/ground are reaching the beacon but it still fails to operate (common with sealed LED units), replace the entire beacon light assembly.

5. 5

   Test and Clear Codes

   After repairs are made, turn on the beacon light to ensure it draws the correct current and functions as expected, then reset the power module (RLC/BCU) or cycle the key to clear the diagnostic trouble codes.