John Deere 3353.15 – CCU: Alternator 1 Status - Data Valid But Above Normal Operating Range - Least Severe Level

The alternator is operating above its normal temperature or load parameters, but the data is still valid. The dashboard message 'Alternator Fault. Over Heating, Turn Off Some Lights' advises the operator to immediately shed excessive electrical load to prevent the alternator from burning out.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 8000 / 8000T Series Tractors
• 8100T
• 8200T
• 8300T
• 8400T
• 8320
• 8420T
• 9000 Series Tractors
• 9120
• 9220
• 9320
• 9420
• 9520
• 9620
• 7000 / 7010 Series Tractors
• 1470 Combine
• 1570 Combine

1. 1

   Reduce electrical load by turning off non-essential draws (extra work lights, cab blowers, A/C) to see if the code clears or the alternator cools down.

2. 2

   Inspect the alternator and batteries for accumulated dirt, chaff, or debris blocking cooling fins.

3. 3

   Verify the alternator drive belt tension and condition for signs of slipping.

4. 4

   Test battery health, as old or failing batteries force the alternator to run at maximum output continuously.

5. 5

   Check for loose, corroded, or damaged battery terminals and clean the main chassis ground.

6. 6

   Perform an alternator output test using a multimeter to check voltage and amperage.

1. 1

   Clean the Unit

   Blow out the alternator, battery box, and surrounding engine bay with compressed air to remove insulating debris.

2. 2

   Service the Batteries

   If the batteries failed the load test or are several years old, replace them. Clean the battery terminals and the main ground strap connection to the chassis.

3. 3

   Replace the Belt

   If the drive belt or tensioner is worn, replace it to ensure the alternator pulley is being driven without slippage.

4. 4

   Replace the Alternator

   If the batteries and wiring are good, but the alternator continues to overheat or fails a bench test, the internal voltage regulator or windings are likely failing. Disconnect the negative battery cable, remove the serpentine belt, disconnect the electrical harness from the alternator, and unbolt the unit. Install the new alternator and re-tension the belt.

5. 5

   Clear Codes

   Reconnect the batteries, start the tractor, and run it at operating RPM (above 2000 RPM) with the lights on to verify the CCU no longer triggers the 003353.15 code.