Case IH 3651 – Engine Control Unit (EDC / Engine ECU): Battery Voltage Uncorrect

Battery voltage: SRC low for battery voltage sensor, meaning the source voltage being detected by the sensor is below the acceptable operating range.

• Farmall
• skid steer
• SR200
• SR250
• SV250
• TR270
• TV380
• Farmall 95A
• Farmall 105U
• Magnum
• Steiger
• Puma

1. 1

   Test resting battery voltage with a multimeter (should be ~12.6V) and perform a load test to ensure it can hold a charge.

2. 2

   Check alternator output voltage at the battery terminals with the engine running (should be 13.8V - 14.7V, ideally 14.4V).

3. 3

   Perform a voltage drop test between the positive battery terminal and the alternator output terminal to check for bad connections.

4. 4

   Inspect the engine wiring harness, primary ground straps, and battery terminals for chafing, shorts, open circuits, corrosion, or looseness.

5. 5

   Verify the alternator belt is not loose or slipping.

1. 1

   Disconnect power

   Always disconnect the negative battery cable first to prevent accidental shorts.

2. 2

   Clean connections

   Clean the battery terminals, cable clamps, and chassis ground connections with a wire brush. Tighten any loose ground straps.

3. 3

   Replace the battery

   If the battery failed the load test, remove the hold-down bracket and install a new heavy-duty tractor specification battery.

4. 4

   Replace the alternator

   If alternator output is low, reading below 13V, relieve tension on the alternator belt and remove it. Disconnect electrical connectors, remove mounting bolts, and extract the faulty alternator. Install the new alternator, torque bolts to spec, reconnect wiring, and reinstall the belt.

5. 5

   Repair wiring

   If the harness is damaged or showed a significant voltage drop, splice in repair connectors or replace the damaged battery cables.

6. 6

   Verify repair

   Reconnect the battery, clear the stored fault codes from the ECU using a diagnostic tool, and run the machine to confirm stable system voltage.