2013-2018 Nissan Altima Alternator: Diagnosing Whining Noises & Charging Failures

Symptoms of a Failing 2013-2018 Altima Alternator

When the alternator in your Altima begins to fail, it will usually provide several warning signs. Ignoring these can leave you stranded, as the vehicle will only run off the battery for a short time before it's completely drained.

Common Failure Indicators:

• Whining or Grinding Noises: One of the most common symptoms is a distinct whining or grinding sound coming from the engine bay. This noise is often caused by worn-out bearings inside the alternator and will typically change pitch with the engine's speed.
• Dimming or Flickering Lights: If you notice your headlights, interior lights, or dashboard lights seem dim, flicker, or get brighter as you accelerate, it's a classic sign the alternator isn't producing a consistent electrical current.
• Battery Warning Light: The most direct indicator is the battery warning light (often shaped like a battery or labeled "ALT") illuminating on your dashboard. This light specifically signals a problem within the charging system.
• Slow or Malfunctioning Electronics: Power windows that operate slower than usual, a radio that cuts out, or other strange electrical behavior can point to an alternator that can't keep up with the vehicle's power demands.
• Difficulty Starting or a Dead Battery: A failing alternator cannot properly recharge the battery. This can lead to a weak or dead battery, making the car difficult to start. If you need to jump-start your car frequently, the alternator is a likely culprit.
• Burning Smell: A smell of burning rubber or hot wires can indicate an overworked alternator or a slipping drive belt.

Known Issues, TSBs, and Recalls

While research did not uncover any widespread recalls or Technical Service Bulletins (TSBs) specifically for alternator failure on the 2013-2018 Altima, it's always a good practice to check for any open recalls on your specific vehicle. There was a recall for the hood latch mechanism on these models (NHTSA Campaign Number: R21A6) which is unrelated to the alternator but important for safety.

Diagnosing the Alternator

You can perform a simple test with a multimeter to check the health of your charging system.

1. Test Battery Voltage (Engine Off): Set your multimeter to DC volts. With the engine off, connect the red probe to the positive battery terminal and the black probe to the negative terminal. A healthy, fully charged battery should read around 12.6 volts. If it's below 12 volts, the battery may be the issue.
2. Test Alternator Output (Engine Running): Start the engine. The multimeter reading should jump to between 13.7 and 14.7 volts. This indicates the alternator is charging the battery.
3. Load Test (Engine Running): With the engine still running, turn on all major electrical accessories: headlights on high beam, A/C or heater fan on high, radio, etc. The voltage should remain steady, above 13 volts. If the voltage drops significantly (e.g., back down to battery voltage), the alternator is likely failing under load.

Buying a Used 2013-2018 Altima Alternator

A quality used OEM alternator can be a reliable and cost-effective alternative to expensive new parts or lower-quality aftermarket units. Here’s what to inspect:

• Verify Part Numbers: The most crucial step is to match the OEM part number. The original alternator is made by Mitsubishi. Look for numbers like A2TJ1881, 23100-3TA1A, 23100-3TA1B, or 23100-9HU0A on the casing.
• Check the Pulley: Spin the pulley by hand. It should spin smoothly and freely in one direction with no grinding, roughness, or wobble. The internal clutch mechanism should prevent it from spinning easily in the reverse direction.
• Inspect the Casing: Look for any cracks, heavy corrosion, or signs of fluid leaks (oil or coolant) on the alternator's body. A casing saturated with oil can lead to premature failure.
• Examine Electrical Connections: The main B+ terminal stud should be straight and the threads should be clean. The plastic connector housing should be intact, without any cracks or broken locking tabs.
• Consider Mileage: Alternators on these vehicles typically last between 80,000 and 150,000 miles. A used unit from a lower-mileage vehicle (under 100,000 miles) is a safer bet and offers a better service life.

Cost to Replace a 2013-2018 Altima Alternator

The cost can vary significantly based on the type of part you choose and local labor rates. A DIY replacement can save you a considerable amount in labor costs.

Replacement Overview & Torque Specs

Replacing the alternator on a 2.5L Altima is an intermediate-level job that can be done at home with the right tools. The estimated time is between 1.5 and 3 hours.

Key Steps:

1. Disconnect the Battery: Always disconnect the negative battery terminal first using a 10mm wrench to prevent electrical shorts.
2. Remove Serpentine Belt: You will likely need to remove the front passenger-side wheel and a plastic splash shield to access the belt tensioner. Use a wrench (often 17mm) on the tensioner to relieve pressure and slip the belt off the alternator pulley.
3. Disconnect Electrical Connectors: Remove the rubber boot and unbolt the main power cable from the B+ terminal (12mm nut). Unplug the smaller wiring harness connector.
4. Unbolt the Alternator: The alternator is held in place by two 13mm bolts. Remove these to free the unit.
🎬 See a visual walkthrough of removing and installing the unit.
5. Installation and Torque: Installation is the reverse of removal. When tightening the new alternator:
• Alternator Mounting Bolts (13mm): 18 ft-lbs
• B+ Terminal Nut (12mm): 8 ft-lbs (or 96 in-lbs). Be careful not to overtighten.
• Wheel Lug Nuts (21mm): 83 ft-lbs

Frequently Asked Questions (FAQ)