Buy Nissan Altima Alternators

The alternator-also called a charging unit or car generator-keeps a Nissan Altima's battery full and powers every electrical load while the engine runs. It spins by a belt on the crankshaft and makes about 13.8 - 14.4 volts, enough for the lights, stereo, and engine computer. When it stops working, the car soon stalls because the battery alone can't run the system. (Wikipedia)

Inside the housing, a rotor (an electromagnet) spins inside a stationary stator. The magnetic field makes alternating current, which a diode bridge turns into direct current. A small wire from the engine computer tells the alternator how hard to work. On late-model Altimas, Nissan's Variable Voltage Control System lowers output during light electrical loads to save fuel, using a battery-current sensor on the negative cable. (Automotive Tech Info, JustAnswer)

• Output rating: Most 2.5 L Altima alternators are 110-130 amps; some trims with more gadgets use up to 150 amps. (Wikipedia)
• Generations:
  • 2002-2006 (L31) use a 4-pin regulator plug.
  • 2007-2012 (L32) add smart charging; output commanded by the ECM.
  • 2013-2018 (L33) and 2019-present (L34) share a similar form-factor but amperage may vary. Always match the part number from the Factory Service Manual (FSM) before ordering. (NICOclub)
• Belt type: A single serpentine belt drives the alternator, water pump, and A/C. Replace a cracked belt right away to avoid sudden charging loss. (YouTube)

• Dashboard battery light or "CHECK CHARGING SYSTEM" message. (AAA)
• Dim or flickering headlights that get brighter when revving. (AAA Club Alliance)
• Electrical gremlins-radio resets, power window slowdown, or erratic gauges. (AAA Oregon/Idaho)
• Engine stall or rough idle once the battery is drained. (AAA Club Alliance)
• Burning-rubber or hot-wire smell from belt slippage or overheated windings. (Firestone Complete Auto Care)
• Growling/whining noise from worn alternator bearings. (AAA Club Alliance)

1. Voltage test: With the engine idling, probe the battery; 13.8-14.4 V means healthy. Below 13 V or above 15 V points to trouble. (JustAnswer)
2. Load test: Turn on headlights, rear defroster, and blower-voltage should stay above 13 V. (Automotive Tech Info)
3. Fuse inspection: The ALT-S 140 A fusible link lives in the under-hood fuse box; replace if blown. (YouTube)

Swapping the unit on 2013-2018 sedans takes about 1½ hours with hand tools: disconnect battery, loosen belt tensioner, remove two mounting bolts, unplug the regulator, and reverse steps with the new alternator. A how-to video walks through every step. (YouTube)

National data show the typical alternator replacement on a late-model Altima runs $750-$850 (parts plus labor), but costs can climb if the belt, tensioner, or battery also need service. (Kbb.com)

While no large-scale U.S. recall targets Altima alternators alone, owners should still check the free Nissan Recall Lookup tool with their VIN for any charging-system campaigns. If you suspect a safety-related failure-such as sudden power loss-you can also file a complaint with NHTSA. A 2013 technical service bulletin (TSB NTB13-040) addressed alternator noise and directed dealers to install an updated unit on certain QR25DE engines. (Nissan Club)

• Keep battery terminals clean so the smart-charging sensor reads correctly. (JustAnswer)
• Replace the serpentine belt every 60 k miles or if glazing appears. (YouTube)
• Avoid adding high-current accessories directly to the battery negative post; doing so bypasses the current sensor and confuses the charging computer. (Club Frontier)
• Let the engine bay cool before washing-rapid temperature change can crack alternator diodes. (Automotive Tech Info)

Alternators contain copper and aluminum that can be recycled. Most repair shops give a core credit for the old unit, which keeps heavy metals out of landfills and reduces mining demand. (Wikipedia)

Q: What does an alternator do?
A: It turns engine power into electricity to recharge the battery and run lights, ignition, and other electronics.

Q: How long should an Altima alternator last?
A: On average 7-10 years or 80,000-150,000 miles, depending on heat, driving habits, and electrical load. (AutoZone.com)

Q: Can I drive with a bad alternator?
A: Only for a short distance. Once the battery voltage drops, lights dim and the engine will quit, possibly leaving you stranded. (AAA)

Q: Why does voltage sometimes dip to 12 V while driving?
A: The variable-voltage system lowers output to cut fuel use when the battery is charged and loads are light; that's normal unless warning lights appear. (Automotive Tech Info)

Q: My battery light flashes but the battery is new-what's wrong?
A: The light signals low charging voltage; a worn belt, loose wiring, or failing alternator diode can trigger it even with a healthy battery. (AAA Club Alliance)

Q: What causes the burning-rubber smell?
A: A slipping belt or overheating alternator windings generate that odor; inspect both before damage spreads. (Firestone Complete Auto Care)

Q: Where is the alternator fuse?
A: In the under-hood fuse box, look for the large ALT-S fusible link (usually 140 A) near the battery positive terminal. (YouTube)

Q: Does higher amperage mean better?
A: Only if you've added big audio amps or other high-draw accessories. Stock electronics work fine with the factory rating, and too much amperage can strain wiring. (Wikipedia)

Q: Are remanufactured units okay?
A: Yes, as long as they meet OEM specs and include new diodes, bearings, and regulator. Always compare the plug shape and mounting ears to your old unit. (NICOclub)

Q: How do I reset the battery-current sensor after replacement?
A: Disconnect the negative cable for five minutes, then idle the engine for 30 seconds with no accessories on. The ECM relearns baseline current flow automatically. (Automotive Tech Info)

Q: What else should be replaced with the alternator?
A: Inspect the belt, belt tensioner, and battery. A weak battery forces the alternator to work harder and fail sooner. (AAA Oregon/Idaho)

Use these tips and links to keep your Nissan Altima's charging system healthy and your ride worry-free.