John Deere 167.04 – ICC: Alternator Voltage Below Normal / System Voltage Circuit Fault

The alternator voltage has dropped below the normal operating range, meaning the alternator is not charging the battery adequately. This can be caused by a faulty alternator, a defective voltage regulator, wiring harness issues, or a defective battery.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5045E
• 5055E
• 5065E
• 5075E
• 5065M
• 5075M
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5095M
• 5095MH
• 5105M
• 5015ML
• 5090M
• 5105ML
• 319E
• 323E
• 330G
• 331G
• 332G
• 333G
• 670D
• 672D
• 770D
• 772D
• 870D
• 872D
• 770G
• 770GP
• 772G
• 772GP

1. 1

   Test the battery to ensure it can hold a charge and is not internally shorted or defective

2. 2

   Inspect the wiring harness and connections between the alternator, battery, and the ICC (Dash Module) for loose connections, corrosion, or broken wires

3. 3

   Measure the voltage output directly at the alternator while the engine is running to determine if the alternator or the internal voltage regulator has failed

1. 1

   Secure the Machine

   Turn off the engine, remove the key, and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Repair Wiring

   If the diagnostic checks revealed damaged wiring or corroded terminals, repair or replace the affected sections of the harness and clean all ground connections.

3. 3

   Replace Battery

   If the battery failed the load test, replace it with a new unit matching OEM specifications.

4. 4

   Replace Alternator

   If the alternator is not outputting the correct voltage (and wiring is intact), the alternator (which typically houses the internal voltage regulator) must be replaced. Remove the serpentine/drive belt, disconnect the electrical connections at the rear of the alternator, unbolt the unit from its mounting bracket, and install the new alternator.

5. 5

   Reassemble and Test

   Reinstall the drive belt, reconnect the battery, start the engine, and verify that the ICC no longer displays the 000167.04 fault code and that system voltage has returned to normal operating range.