John Deere 002378.05 – CLC: Tail Light Circuit Low Amperage

The Cab Load Center (CLC) control unit has detected a lower-than-expected electrical current (typically below 0.5 amps) in the tail light circuit. This indicates an open circuit or low current condition, meaning the electrical flow to one or more tail lights is weak, interrupted, or non-existent.

• 7200R
• 7210R
• 7215R
• 7230R
• 7250R
• 7270R
• 7290R
• 7310R
• 7630
• 7730
• 7830
• 7930
• 8225R
• 8235R
• 8245R
• 8260R
• 8270R
• 8285R
• 8295R
• 8295RT
• 8310R
• 8310RT
• 8320R
• 8320RT
• 8335R
• 8335RT
• 8345R
• 8345RT
• 8360R
• 8360RT
• 8370R
• 8370RT
• 8400R
• 8130
• 8230
• 8330
• 8430
• 8530
• 9360R
• 9370R
• 9410R
• 9420R
• 9420RX
• 9460R
• 9460RT
• 9470R
• 9470RT
• 9470RX
• 9520R
• 9520RT
• 9520RX
• 9530
• 9630
• 9230
• 9330
• 9430
• 7210J

1. 1

   Cycle the tractor's main power off and on to clear potential intermittent communication errors

2. 2

   Visually inspect the tail lights for obvious damage, cracked lenses, or moisture ingress

3. 3

   Check the tail light bulb (especially dual-filament bulbs) and test with a known good bulb

4. 4

   Inspect the lighting circuit fuse in the vehicle's fuse box

5. 5

   Inspect the light socket for corrosion (green/white powder), dirt, or bent pins

6. 6

   Test for a steady 12V supply at the light socket with the lights switched on using a multimeter

7. 7

   Check the ground wire from the light assembly to the chassis for a clean, tight, and rust-free connection, and consider running a temporary ground wire to a known good ground to see if the fault clears

8. 8

   Inspect the wiring harness and multi-pin connectors from the tail light to the cab for chafing, rodent damage, or pinched wires

9. 9

   Verify the CLC lighting configuration addresses (especially if lights were changed or software was updated)

1. 1

   Disconnect power

   Turn off the tractor and disconnect the battery before beginning electrical repairs for safety.

2. 2

   Access the faulty light

   Remove any guards or covers to access the rear of the tail light assembly.

3. 3

   Replace the bulb

   If diagnosing a burned-out bulb (most common cause), twist to remove the bulb socket from the housing, replace the bulb with a new one of the correct type, and re-insert the socket.

4. 4

   Clean connections

   If diagnosing a corroded socket or connector, clean the pins using a small wire brush and electrical contact cleaner. Allow it to dry and apply dielectric grease for future protection.

5. 5

   Repair wiring

   If diagnosing a damaged harness, cut out the bad section of wire. Splice in a new piece of wire of the same gauge using heat-shrink butt connectors to ensure a sealed repair.

6. 6

   Secure ground connection

   If diagnosing a bad ground, remove the ground bolt or screw, clean the contact area on the chassis down to bare metal, and re-secure the ground wire tightly.

7. 7

   Test the repair

   Reconnect the battery, turn on the lights, and check if the tail light is functioning correctly. Verify the fault code has cleared from the display.

8. 8

   CLC Calibration

   If the physical circuit is sound but the fault persists (configuration cause), contact a John Deere dealer to inspect and recalibrate the CLC lighting configuration addresses using service tools.