John Deere 520715.03 – CLC / RLC: Pressurizer Blower Motor Voltage High

The control module is detecting a higher-than-expected voltage on the cab pressurizer blower motor circuit, which typically points to a short-to-power in the wiring harness, an open circuit (which can cause the voltage reading to float high), or an internal failure of the blower motor itself.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8245R
• 8400R
• 9470RT
• 9520RT
• 9570RT
• CH570
• CH670
• 3520

1. 1

   Verify the code on the cab monitor to confirm if it is active or stored under the CLC or RLC module.

2. 2

   Inspect the wiring harness connecting the CLC/RLC to the cab pressurizer blower motor for chafed wires that may be shorting to a 12V power source.

3. 3

   Inspect the connectors at the motor and the module for disconnected plugs, pushed-back pins, or heavy corrosion (an open circuit can trigger a .03 Voltage High code).

4. 4

   Bench test the motor by disconnecting it and applying direct 12V power and ground. If it fails to spin or draws abnormal amperage, the motor has failed internally.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical shorts or spikes during the repair.

2. 2

   Access the Motor

   Locate the pressurizer blower motor. Depending on the machine, this is typically housed in the cab roof assembly or the external HVAC fresh-air intake housing.

3. 3

   Disconnect Electricals

   Unplug the electrical harness connector from the blower motor.

4. 4

   Repair Wiring

   If the diagnostic checks revealed a short-to-power or damaged connector, repair the wiring harness or splice in a new pigtail connector.

5. 5

   Replace the Motor

   If the motor is faulty, remove the mounting screws/bolts, extract the old pressurizer blower motor, and install the new OEM replacement motor. Secure it in the housing.

6. 6

   Reassembly

   Reconnect the electrical harness and re-install any cab roof panels or access covers.

7. 7

   Test the System

   Reconnect the battery, turn the key on, and use the cab monitor to clear the stored CLC/RLC fault codes. Run the HVAC system to verify that the cab pressurizes properly and the code does not return.