Skip the auto shop - Our mechanics make house calls

Q: Possible alternator problem

asked by on

How can I tell if the alternator needs to be replaced?

A: Hi. An illuminated dashboard charging light...

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. One way is to check charging system output with a digital multimeter. The other is to test the starting/charging system with a professional digital test machine. The second way is the easiest and is the most comprehensive. If you need further assistance, I recommend you have a certified technician, like one from YourMechanic, diagnose the starting issue and replace any failing parts.

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: Hi Ben I noticed That when i took the inertia switch out my truck I heard something one is rattling is that normal

The inertia switch has a metal ball inside the switch that will make contact between the two terminals of the switch when working properly. The inertia switch is designed to move the ball away from the contacts in a roll...

Q: Electricity gauge reading low voltage. Just charged my battery and replaced alternator in April. Connections look good.

Hello - the first thing to check is the electrical system voltage with the engine running at a fast idle - which should be 13 volts or above. Check this with a known good voltage meter - auto gauges are...

Q: Car won't crank. I think its the timimg belt

Hey there. I'm a little confused by your issue. If your car's engine won't crank over, it typically is related to the starter motor or ignition system. A broken timing belt will prohibit the motor from spinning over, but you'll...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.