Alternator replacement:

Find out how to check and repair a car alternator

Estimated time required - 2 hours

Car alternator replacement: discover how to check and replace your car alternator yourself.

Your car alternator is an electrical generator. Your engine spins the alternator through a system of belts and pulleys. As the alternator spins, it makes electricity in the form of alternating current.

Over time, the parts inside your alternator wear out and make less electricity. Alternators can also malfunction and make too much power. Too much power can cause your battery to overcharge and fail. The alternator and car battery must work together properly so your vehicle can make and store electricity.

Stop into the Advance Auto Parts store nearest you for a free charging system test. We can tell you what's right or wrong with your charging system, and recommend if it’s time for an alternator replacement. We carry a full line of alternator parts.

Why you should remove and replace your car alternator:
Your alternator provides electricity while the engine is running.

Part of the alternator's job is to recharge the battery. The battery only stores electricity for later use. If your alternator parts fail, your battery will quickly lose power. After the battery drains, not only will your car stop running – it won't start!
Don’t get left in the dark. Keep your alternator parts and charging system in peak condition. Advance Auto Parts will check your charging system at any time for no charge.

What you will need for a car alternator replacement:

An alternator replacement guide: do it yourself & save!

Disconnect the negative battery post before starting. A serpentine belt tensioner can cause injury. See the article on auto belts and hoses for more belt help. Consult a repair manual for your vehicle.

  1.  A serpentine belt is flat and thin. A V-belt is V shaped. If you have a V-belt, skip to step 4. Replace any belt if worn, frayed, glazed or cracked.

  2.  To loosen a serpentine belt, first find the tensioner. The tensioner is spring loaded. It keeps the belt tight.

  3.  Loosen the tensioner. Leave room for the spring backlash. Be careful not to trap or injure your hand. Loosen and remove the belt.

  4.  Remove the wiring harness, connectors or wiring and fasteners from the alternator. Mark multiple wires with tape and labels so you don’t forget where they go.

  5.  Loosen and remove the alternator. If you have a V-belt, the alternator must be loosened before removal. The alternator also provides belt tension on the V-belt.

  6.  Install the new alternator, making sure that it fits properly and aligns with the existing bolt holes. Reverse the disassembly procedure. Check for the correct belt tension.

  7.  Reconnect the negative battery terminal. Attach the voltmeter to the battery and start the vehicle. Check for proper voltage. Your alternator output should read from 13.1-16.5 volts.

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For high quality auto parts on all of your vehicle maintenance – including alternator parts – trust Advance Auto Parts!