Skip the auto shop - Our mechanics make house calls

Q: High voltage alternator

asked by on

The battery in my car was bonkers. I found out the alternator was working at 17 volts. Now all of the sensors in the car are on when the car is moving. Even the engine revs high. Is the alternator causing these things to happen? What should I do?

A: Most alternators have a voltage regulator i...

Most alternators have a voltage regulator integrated within them. This voltage regulator is responsible for making sure that the battery is charged right around 14 volts. If your alternator is producing 17 volts, it is almost a certainty that the voltage regulator within has failed.

I would recommend having your alternator replaced by a qualified technician to ensure that no other electrical problems result from the overcharging of your battery. If the battery continues to be overcharged for a long period of time, the other electronics of the vehicle may show signs of damage as a result of this.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Loud banging from driver's side rear of car

Hello. A banging noise can come from many different parts in the rear of your vehicle. Typically if the noise only occurs intermittently then it is not a bearing. A bearing tends to make more of a rubbing or roaring...

Q: My car will not start. I changed the head gasket an now it will not start.

If your car was not running and a computer update got it running but the engine would shut off so you did a tuneup, brakes and a head gasket. You might have problems with the installation of the head...

Q: Possible alternator problem

Hi. An illuminated dashboard charging light is almost a sure sign that the alternator needs to be replaced. If the light is not on and you suspect a problem with the alternator, there are a few ways to test it....

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.