John Deere 2320 Alternator Replacement: 60 Amp Denso Unit (2006-2008)

Author : Danny walker | Published On : 09 Oct 2026

If your John Deere 2320 won’t hold a charge, cranks slowly, or has headlights that dim and flicker, the alternator is the first thing to check. The battery starts the Yanmar diesel, but once the engine is running, the John Deere 2320 Diesel Tractor Alternator 60 amp unit takes over. It powers the lights and electrical system and recharges the battery for the next start.

When it fails, the tractor runs on whatever charge the battery has left. Watch for a battery that keeps going flat, weak or flickering lights, a dash warning light, slow cranking, or everything cutting out after the tractor has been running. Ignoring these signs can leave you stranded and strain the starter.

Before buying a new battery, test the charging system. With the engine running, a multimeter across the battery terminals should read about 13.5 to 14.5 volts. If it stays near the resting battery voltage, the alternator isn’t charging.

This new 60 amp unit has an internal regulator and internal fan (IR/IF). The regulator keeps voltage steady as engine speed and load change, and the fan carries heat away. It replaces Denso 101211-2590, 101211-2591, 101211-284, 101211-2840 and 101211-2841, Lucas LRA01857, and Yanmar 129961-77200. It’s listed for the 2320 only (3-cylinder, 24HP, 2006-2008), so check your old unit’s number and compare the pulley, plug position, and mounting points before ordering. Note that it’s described as Denso-style, so ask the seller if you need a genuine Denso part.

Installing is a manageable weekend job. Disconnect the negative cable first, photograph the wiring, and follow your service manual for torque specs and belt tension. Confirm the part number, then order from Denparts and get your 2320 charging again.

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