Alternator Repair at your home or office.

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How much does Alternator Repair cost?

It depends on the type of car you drive and the auto repair shop you go to. Our mechanics are mobile, which means they don't have the overhead that repair shops have. They provide you convenience by coming to your home or office.

Cars Estimate Parts Cost Labor Cost Savings Average Dealer Price
2004 GMC Envoy XUV $305 $234.65 $70.00 10% $342.15
2006 GMC Sierra 2500 HD $348 $278.18 $70.00 9% $385.68
2014 Ford Transit Connect $319 $249.38 $70.00 10% $356.88
2004 Mercedes-Benz CLK320 $362 $278.38 $84.00 11% $407.38
2009 Audi Q7 $1506 $1421.98 $84.00 2% $1550.98
2012 Jaguar XJ $583 $457.18 $126.00 10% $650.68
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Alternator Repair Service

What is an alternator and how does it work?

The alternator, which is bolted to the engine, keeps your car’s battery charged and produces the electrical power necessary to run the vehicle’s electrical systems. When starting your car, stored energy in the battery powers the starter motor. Once the engine is running, the alternator produces the electrical energy that your car needs by spinning a magnet on a rotor through a stationary coil of wire. To ensure that the alternator provides the right voltage output for your car’s electrical system, there is a voltage regulator built into the alternator. The voltage regulation is built into the car’s Powertrain Control Module (PCM) on newer vehicles.

Alternator

When to replace the alternator?

The following electrical or mechanical faults are signs that the alternator may need to be replaced:

  • Battery or charging system warning light. If a warning light has illuminated, the charging system and the vehicle battery should be tested to pinpoint the fault.
  • Difficulty starting your car or it doesn’t start. A faulty alternator will lead to the battery being discharged. Once the battery has discharged enough, you will have difficulty starting your car or it won’t start at all.
  • Dimming lights. Should the alternator have an internal electrical fault, such as a burned-out diode or open stator windings, the alternator will have less capacity to provide electrical power.
  • Grinding or whining noise. High heat created by the engine dries out the grease in the alternator bearings, wear occurs, and then the alternator can emit a grinding or whining noise as it spins. Certain electrical failures within an alternator can also cause a whining noise.
  • Premature Battery Failure. If the voltage regulator within the alternator has failed, and thus charging system output is too high, that can cause the battery to fail due to overcharging. Although this fault is not as common as a weak alternator, the possibility should always be considered if your car battery fails prematurely.
  • On an annual basis, or every 12,000 miles. The voltage output of the alternator should be carefully measured and compared to the OEM factory specification. Voltage output should also be checked whenever the vehicle battery is replaced.

How do mechanics replace an alternator?

  • Disconnect the battery prior to replacing the alternator, as with all electrical repairs.
  • Unhook the drive belt connected to the alternator.
  • The electrical connections to the alternator are removed and the alternator is unbolted from its cradle on the engine.
  • The new alternator is installed while observing all factory bolt torque specifications. Alternators have to be mounted to the engine very securely because they rotate at high speed. Electrical connections are cleaned and re-attached, including the connections to the battery.
  • While the drive belt is off, best practice is to inspect the drive belt as well as inspect all pulleys driven by the belt.
  • Once all components are securely in place, the vehicle engine is run and the output of the new alternator is measured and verified against the OEM factory specification.

Is it safe to drive with an alternator problem?

One should exercise caution. Should the alternator fail while you are driving, the battery alone will power the car’s electrical system for a short while. Cars require a substantial amount of electrical power though and the battery will likely discharge relatively quickly. The car may stall and it would be impossible to re-start if the battery discharged completely. When the battery or charging system warning light illuminates, the situation should be investigated and resolved as soon as possible.

When replacing the alternator keep in mind:

  • An alternator should always be tested to be sure it is actually faulty versus a circumstance where faulty electrical connections, or an open fuse, might be the problem.
  • An alternator that has noisy or worn out bearings should be replaced regardless of electrical test results.
  • A properly functioning battery is very important in modern cars and consequently the battery should be load tested when the alternator is replaced.
  • Alternators are designed to power all vehicle electronics and maintain a fully charged battery but if the battery has failed and won’t hold a charge, attempting to continually re-charge such a battery by driving can overload the alternator. Replace the battery and avoid repeatedly jump-starting your car.
  • Electrical connections, including grounds, are very important in the charging system. When replacing the alternator, all disconnected terminals should be inspected and cleaned and then checked to be sure all connections are properly tightened.

Fast and easy Alternator Repair service at your home or office.

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Recent Alternator Repair reviews

Excellent Rating

YourMechanic Alternator Repair Service

Average Rating

4.9/5

Number of Reviews

3,751

Rating Summary
3,529
131
28
16
47
3,529
131
28
16
47

Noe

33 years of experience
525 reviews
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Noe
33 years of experience
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by Usa
I had Noe service my car. He was the friendliest, most honest mechanic I have ever met.
2007 TOYOTA CAMRY - ALTERNATOR - SEATTLE, WASHINGTON

Jason

14 years of experience
427 reviews
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Jason
14 years of experience
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by C.
2008 HONDA ODYSSEY - ALTERNATOR - MOUNTAIN VIEW, CALIFORNIA

Cesar

6 years of experience
215 reviews
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Cesar
6 years of experience
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by Michael
Cesar was on time and got right to work. He coplteted in the estimated time and cost. He let me know a couple of things I needed to do but didn’t try to push any sales.
1996 FORD EXPLORER - ALTERNATOR REPAIR - BOTHELL, WASHINGTON

Stefan

14 years of experience
366 reviews
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Stefan
14 years of experience
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by
Stefan was great!. I have a very tiny car that unfortunately doesn't have much clearance for working on it. To replace my alternator Stefan had a lot of work cut out for him, and he did an amazing job with it. He was able to come out to my house on short notice and stand out in the freezing cold to fix my car.I was quoted a few different prices for an alternator replacement, YourMechanic had the lowest price. They are friendly and thorough! I love YourMechanic.com and will absolutely be recommending them to everyone!
2003 CHEVROLET CAVALIER - ALTERNATOR - HAYWARD, CALIFORNIA
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