Symptoms of a Bad or Failing Alternator

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Cost of Replacing a Bad or Failing Alternator

Common signs include having to jump start the car frequently, dim lights when operating the vehicle, or the Battery Light coming on. Our certified technicians can come to you and diagnose the problem. You will receive a $30 credit towards any follow-up repairs that result from the diagnostic. Following are example prices for Alternator Repair. Click on the button below to get an upfront quote for your car.

Cars Estimate Parts Cost Labor Cost Savings Average Dealer Price
2012 Nissan Armada $330 $218.38 $112.00 15% $390.38
2013 Mazda 3 Sport $438 $368.50 $70.00 7% $476.00
2011 Mitsubishi Lancer $356 $264.58 $91.00 12% $404.33
2003 Acura RL $375 $291.18 $84.00 10% $420.18
2012 Mercedes-Benz ML350 $1605 $1534.54 $70.00 2% $1642.04
2003 BMW M5 $354 $200.18 $154.00 18% $436.68
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How to Diagnose a Bad or Failing Alternator?

bad alternator

The electrical charging system is one of the most important systems on any vehicle. The charging system is made up of several components, including the alternator and battery, that work together to supply all of the vehicle’s electrical needs. The alternator is what specifically generates the amperage and electricity required to meet the vehicle’s electrical needs, including keeping the battery charged.

Because the alternator plays such a vital role in keeping all of the vehicle’s electrical components powered, any problems with the alternator can quickly develop into problems with another system or component on the vehicle. Usually, a defective or failing alternator will produce a few symptoms that can alert the driver of a potential issue, allowing time for the driver to service the vehicle before a bigger problem occurs.

1. Having to jump start the vehicle on a regular basis

One of the first symptoms of a bad or failing alternator is the need to jump start the vehicle on a regular basis. It is the job of the battery to provide the power to crank the engine and start the vehicle, however, it is the job of the alternator to make sure that the battery stays charged. If the alternator is beginning to have problems or has failed, it will not be able to meet the vehicle’s electrical needs, including keeping the battery fully charged. A low or uncharged battery will not be able to keep up with the load required to start an engine multiple times, and will result in a dead battery. Continuously having to jump start the vehicle may be a sign that the alternator may not be charging the battery and is therefore unable to successfully start a vehicle.

2. Dim lights

Another symptom of a potential problem with the alternator is dim or flickering lights. If you notice any sort of flickering or dimming of the lights when operating the vehicle, it may be a sign that the alternator is not generating enough power to keep up with the vehicle’s electrical needs. The dimming or flickering may coincide with certain actions when operating the vehicle, such as dimming when pressing on the gas pedal, turning up the volume on the stereo, or turning on another light. This symptom may be indicative of an alternator that is unable to keep up with the needs of the vehicle’s electrical system while it is running, and when additional loads are placed on it.

3. Battery Light comes on

One of the most common symptoms of a problem with the alternator is an illuminated Battery Light. The Battery Light will usually come on when the computer detects that the system voltage has fallen below a certain requirement. This usually means that the alternator, or perhaps one of its internal components, has failed and it is no longer able to keep up with the vehicle’s electrical requirements, and it has been detected by the computer. An illuminated Battery Light also indicates that the vehicle is now running on limited battery life. Depending on the condition of the battery, and how long the Battery Light has been on, the vehicle should be able to run for a short amount of time before the battery finally dies. At that point, the vehicle will shut off and service will be required.

The alternator is among a vehicle’s most important components, as it essentially serves to provide the electrical supply for the entire vehicle. Any problems with it can quickly translate to problems with starting and running the vehicle, which opens up the possibility of being stranded on the road. If you suspect that your vehicle may be having a problem with the alternator, or it is displaying any of the symptoms above, [have the battery and alternator carefully inspected] by a professional technician, such as one from YourMechanic. They will be able to determine if an alternator replacement is necessary, or if another issue needs to be addressed.

electrical system
Charging System
alternators
Battery Light
Batteries

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Recent Alternator Repair reviews

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YourMechanic Alternator Repair Service

Average Rating

4.9/5

Number of Reviews

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Rating Summary
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Michael

13 years of experience
379 reviews
Michael
13 years of experience
Michael was great. First experience with a mobile mechanic and now I wonder why. Efficient, competent, explained everything. Evern put up with me looking over his shoulder for a bit. On time and finished early, I booked him immediately on another issue after I saw how great he was.
2001 CHEVROLET SILVERADO 1500 - ALTERNATOR - KENNESAW, GEORGIA

Honorio

16 years of experience
658 reviews
Honorio
16 years of experience
It was a good experience. Thanks to Honorio!
2006 LEXUS ES330 - ALTERNATOR - PALO ALTO, CALIFORNIA

Michael

24 years of experience
206 reviews
Michael
24 years of experience
Very nice, experienced and thorough. Did a great job and had my alternator in and working in the time frame scheduled.
2005 DODGE DURANGO - ALTERNATOR - MESA, ARIZONA

Tien

20 years of experience
746 reviews
Tien
20 years of experience
Not happy
2006 HONDA PILOT - ALTERNATOR - HAYWARD, CALIFORNIA

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Related questions

Q: I have continuity between my positive and negative terminals with no battery in

It is certainly possible that you have continuity even with the alternator removed. Things like clocks, digital radios with memory, alarm system, and even some modules always pull power from the battery when the vehicle is turned off. That will...

Q: Battery light just came on. What could it mean? Is it safe to drive?

This may be a sign of a weak battery, a failing voltage regulator or failing alternator. As you may know, the alternator is responsible for charging the battery while the engine runs by generating amperage and recharging the battery while...

Q: Q: Alternator not charging the battery.

It is possible that the new alternator may have gone bad as well. From time to time new parts can be bad. There could also be a problem with the fuse in the charging system. I would ask for help...

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