John Deere 3353.07 – ECU: Alternator 1 Status

Alternator Fault - Not Charging With Engine Running. The system has detected that the alternator is failing to output the required voltage/current to charge the battery and power the electrical system while the engine is actively operating.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5085E
• 5095E
• 5100E
• 312GR
• 314G
• 318G
• 319E
• PowerTech PSS/PWS 4.5L FT4
• 4045HFG09
• 4045H1550

1. 1

   Check the battery voltage and perform a load test, as a completely dead or severely undercharged battery can trigger charging faults.

2. 2

   Inspect battery cables and alternator wiring for poor, loose, or heavily corroded connections. Clean them thoroughly.

3. 3

   Inspect the alternator/fan drive belt (V-belt or poly-rib belt) for proper tension, glazing, severe wear, or breakage.

4. 4

   Check the system fusible links, key switch, and start relays to ensure the alternator field circuit is receiving the excitation voltage it needs to begin charging.

1. 1

   Disconnect Power

   Always disconnect the negative battery cable before working on the electrical system.

2. 2

   Belt Replacement

   If the diagnostic checks revealed a slipping or broken belt, use a breaker bar to release the tensioner and install a new OEM drive belt.

3. 3

   Wiring Repair

   Clean the B+ output terminal on the alternator and ensure the wiring harness connector is securely seated. Replace any blown fusible links.

4. 4

   Alternator Replacement

   If the belt and wiring are intact but the alternator fails to output proper voltage (approx. 13.5V–14.5V for a 12V system, or 27V–28V for a 24V system) when the engine is running, the alternator has failed internally. Remove the drive belt, disconnect the electrical connectors from the rear of the alternator, remove the mounting bolts and extract the alternator. Install the new alternator, torque the mounting bolts to OEM spec, and reattach the wiring.

5. 5

   Reassembly & Testing

   Reinstall the drive belt, reconnect the battery, and start the engine. Verify the charging voltage at the battery with a multimeter. Clear the ECU fault codes using a diagnostic scan tool.