John Deere 03 – ACU: Side Finder Electrical System Fault

A fault has been detected in the side finder electrical system, specifically indicating a 'voltage out of range high' condition. The electrical circuit for the side finder auxiliary lights is experiencing a voltage level higher than normal operating parameters. This issue is typically caused by a short circuit to a power source, damaged wiring, poor connections, or a faulty component within the lighting system.

• 9470STS
• 9560STS
• 9570STS
• 9650STS
• 9660STS
• 9670STS
• 9750STS
• 9760STS
• 9770STS
• 9860STS
• 9870STS
• 9540
• 9560
• 9580
• 9640
• 9660
• 9680
• 9450
• 9550
• 9650
• 9500
• 9510
• 9600
• 9610
• 'i' series CTS

1. 1

   Visually inspect the wiring harness leading to the left and right side finder lights for signs of damage, chafing, rodent damage, or corroded connectors

2. 2

   Check for a short to power by tracing the side finder light circuit wiring to identify any points where the wire may be compromised and making contact with a 12-volt source

3. 3

   Test the circuit voltage at the side finder light connector using a multimeter (should read 12-14.5 volts with field lights on and turn signal activated)

4. 4

   Inspect the bulb and light assembly for internal shorting or physical damage

5. 5

   Check all fuses and relays related to the lighting circuits

6. 6

   Consult official John Deere technical manuals (e.g., TM1802 for 9450, 9550, and 9650 combines) for specific diagnostic sections for the side finder lights

1. 1

   Isolate the fault

   Disconnect the side finder light assembly and re-check for the fault code. If the code disappears, the issue is likely within the light assembly itself. If the code persists, the fault is in the wiring harness or the controller.

2. 2

   Repair wiring harness

   If a damaged section of the wiring harness is found, repair it by splicing in a new section of wire with sealed connectors to prevent moisture intrusion.

3. 3

   Replace faulty components

   If the light assembly or bulb is determined to be faulty during isolation, replace it with a new part.

4. 4

   Diagnose control unit

   If all other components and wiring test correctly, the issue may lie within the Armrest Control Unit (ACU). This typically requires diagnosis and replacement by a certified technician.