Does Your Car Need Alternator Repair?



power steering repair

You are wondering if it is your battery or starter?  Then it dawns on you. It could be the alternator.  What is an alternator? What is alternator repair? What does alternator repair cost?  We’ll try to answer your questions.

The Earnhardt Lexus service department handles alternator repair for all makes and models.  So, whatever you drive, we’re the place to bring your car for repairs and maintenance. Our online scheduler gets you started.

What is Alternator Repair?

A typical alternator repair is full replacement.  However, there are many things that can cause the alternator to act up. These include  wiring, charging system control circuitry, or voltage circuitry. It could be a slipping drive belt or alternator pulley (certain late model cars). If it is a belt, the mechanic may need to check for reasons that it is worn.

How much does alternator repair cost?

Your mechanic should be sure it is the alternator before recommending a replacement. This is the most expensive repair. Less expensive repairs include replacing parts such as the wiring, sensors, pulleys or belts.  

If you have been told an alternator repair cost, check with Earnhardt Lexus service department for a second opinion. To show you how competitive we are, we invite you to Dare to Compare.

What does the Alternator do?

Your alternator is part of the electric system, which includes the battery and voltage regulator.  While the battery is the electric power source, it couldn’t generate electrical energy without the alternator.  It delivers power to the battery and the entire car while the car is in motion.

How Long Does an Alternator Last?

The good news is that most can last seven to 10 years.  However, if you drive for a long time on a bad battery or have a bad starter, the chances of developing an alternator problem go up exponentially.  The alternator is the reason you need to keep a relatively fresh battery and stick to your maintenance routine as recommended by your vehicle manufacturer.  

What are the signs of a faulty alternator

Alternator problems can seem much like battery problems. That’s because the supply of power isn’t flowing well, and the battery may not stay charged at its appropriate capacity. Look for these problems:

  • Flickering headlights
  • Slow or troublesome starts
  • Dim dashboard lights

Where is the alternator in the engine?

It is usually near the front of the engine compartment. You may find it by locating the serpentine belt which is part of the crankshaft that drives the alternator. 

The main parts include the voltage regulator, which prevents power surges; diodes, which converts the alternating current into a direct current for the battery; the cooling fan, which may be inside or outside of the alternator;  and the stator and rotor, which are basically magnets that create the spin that converts energy into electricity. 

Is it the battery or starter? The starter or the alternator?

These are the central questions that a person asks themselves when their car won’t start.  Is it the battery vs starter?  They also need to ask if it is the starter or the alternator.

The battery stays charged via the alternator’s alternating current. To get that charge, the voltage regulator must convert the AC into a direct current.  For a spark to get things underway, the starter “turns over” the engine and engages the battery.  

The age of your battery is the first clue. If it is brand new, you most likely have a starter or alternator problem. A  battery should stay charged at 12.5 volts or higher. While some batteries can keep things going for 4 or 5 years, the average is much shorter, especially hot climates like Arizona.

Your mechanic will make sure the problem isn’t the wiring connections. These can be tested for connectivity and for possible faults.

Next up, the battery vs starter. If the starter is the problem, your mechanic will replace it. They will be looking for a weak solenoid or a defective starter drive. Clues here are noisy, chattering starts or slow starts, although sometimes there is simply no start at all.  

Finally, the starter vs alternator.  The alternator directs the action for the battery and starter.  If it is failing, the battery will lose power or die.  The mechanic will check for a proper charging capability.  It should rise quickly when the vehicle starts and then hold the charge.

Tests will be performed to see if there is alternating current leakage. This ripple voltage is caused by bad alternator diodes.  Low charging output may be charged by circuit resistance, which can be measured with a voltmeter.  The mechanic will also check the voltage regulating sensors. Incorrect input may be leading to poor operation.

Moving parts can also be the culprit.  A slipping drive belt can have a bad automatic tensioner that is stuck or weak. This causes the belt to slip.  Sometimes the owner notices a noise during idle with a slipping belt.  A bad alternator pulley is another culprit on certain vehicles.

If it’s not an outside problem to be repaired, then the problem is inside the alternator.  This will mean replacing the alternator. The best way to do that is with original equipment manufacturer (OEM) parts.  However, some alternators may be stressed by aftermarket systems.  Your mechanic may recommend a higher output alternator when possible. If the vehicle is very old, but the owner wants it to keep running, an aftermarket reconditioned alternator may be the best solution.

There’s much to learn about repairing cars. Let us help.  Call or schedule an appointment online.


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