Replacing the alternator in a 2008 Nissan Altima 3.5 is a manageable task for those with basic mechanical skills. This guide will provide clear instructions for DIY enthusiasts looking to save on repair costs while ensuring their vehicle operates smoothly.

Understanding the Alternator's Role

The alternator is crucial for charging the battery and powering the electrical system when the engine is running. A failing alternator can lead to battery drainage, causing electrical failures and starting issues.

Tools Required

Before starting, gather the following tools:

  • 10mm Wrench
  • 10mm Socket
  • 12mm Socket
  • 13mm Socket
  • 14mm Socket
  • Trim Tool Set
  • Ratchet
  • Torque Wrench
  • Gloves
  • Safety Glasses
  • 5mm Hex Socket

Step-by-Step Replacement Process

Step 1: Disconnect the Battery

Begin by disconnecting the negative battery cable using a 10mm wrench. This step is crucial to prevent any electrical shorts during the replacement process.

Step 2: Remove Engine Cover and Air Box

Use a 5mm hex socket to remove the engine cover bolts. Next, take out the air box by removing its two 10mm bolts. This will provide better access to the alternator.

Step 3: Remove the Drive Belt

To remove the drive belt from the alternator pulley, locate the tensioner pulley. Use a wrench to relieve tension and slip the belt off. This step can be tricky, so ensure you understand how your specific tensioner works.

Step 4: Disconnect Alternator Wires

Carefully disconnect all wires from the alternator. Use a 10mm socket for ground straps and other connections. Label wires if necessary to ensure correct reinstallation.

Step 5: Unbolt the Alternator

Remove the bolts securing the alternator using 12mm and 14mm sockets. If space is tight, consider moving other components like the coolant reservoir temporarily.

Step 6: Install New Alternator

Position the new alternator in place, aligning it with bolt holes. Secure it with bolts, tightening them to specified torque values: 35 ft-lbs for bottom bolt and 21 ft-lbs for top bolt.

Step 7: Reconnect Wires and Install Belt

Reconnect all wires to the alternator, ensuring they are secure. Reinstall the drive belt onto the alternator pulley, ensuring proper routing.

Step 8: Reassemble Components

Replace the air box and engine cover, securing them with their respective bolts.

Step 9: Reconnect Battery

Finally, reconnect the negative battery cable using a 10mm wrench.

Important Tips

  • Always wear gloves and safety glasses for protection.
  • Double-check all connections before starting your vehicle.
  • If you encounter difficulties, consult a repair manual or video for visual guidance.

FAQs About Alternator Replacement

    • How long does it take to replace an alternator?
      Typically, it takes about 1-2 hours depending on your experience level.
    • What are signs of a failing alternator?
      Common signs include dimming headlights, electrical issues, or a warning light on your dashboard.
    • Can I drive with a bad alternator?
      It's not advisable as it can lead to battery failure and leave you stranded.