John Deere 2372.03 – CLC: Brake Lights Circuit Voltage High

The Cab Load Center is detecting a higher-than-expected voltage on the brake light circuit. This typically means there is a short to power (a wire touching a live voltage source) or an internal failure within the lighting circuit causing restricted system function.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8225R
• 8245R
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R
• 8370R
• 8400R
• 9470RT
• 9520RT
• 9570RT
• 7630
• 7730
• 7830
• 7930
• 8130
• 8230
• 8300
• 8430
• 8530
• 9230
• 9330
• 9430
• 9530
• 9630

1. 1

   Cycle the key switch to see if the code clears, as recommended by the Operator's Manual

2. 2

   Check the brake light bulbs and their sockets for internal shorts, melting, or severe corrosion

3. 3

   Trace the brake light wiring harness from the rear fenders back to the cab, looking for pinched wires, chafing, or damaged insulation

4. 4

   Inspect the wiring harness connectors at the Cab Load Center for moisture, bent pins, or corrosion

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the negative battery cable to ensure safety while working on the electrical system.

2. 2

   Isolate the Short

   Remove the brake light bulbs. Use a digital multimeter (DMM) to check for voltage at the brake light socket with the brakes disengaged. If voltage is present, there is a short to power in the harness.

3. 3

   Repair Wiring

   If a short is found in the harness (commonly near pinch points like the rear fenders or cab entry points), cut out the damaged section of wire, splice in a new section using weather-sealed heat-shrink butt connectors, and re-loom the harness.

4. 4

   Replace Components

   If the sockets or bulbs are melted/shorted, replace them.

5. 5

   Test the CLC

   Reconnect the battery and cycle the key. If the wiring tests perfectly fine but the code persists and voltage remains improperly high, the Cab Load Center (CLC) itself likely has an internal short and must be replaced.

6. 6

   Clear Codes

   Cycle the tractor power to clear the restricted function state.