Q: How can you tell if your alternator is working properly?

asked by on

I have had to jump the car the last two times I started it.

My car has 90100 miles.
My car has an automatic transmission.

Hi, thanks for writing in. Usually this is identifiable by the charging system gauge in your car, which should typically read, at idle, 13.8 to 14.3 volts with no lights or accessories on (although some may charge at a slightly higher voltage depending on temperature, engine RPM, type of battery, and the battery’s state of charge). This may also be caused by the voltage regulator not working properly. This is a unit that regulates the charging amperage to the battery from the alternator. When this is not working properly, this can cause the alternator to over or under charge the battery as well. I would recommend having an expert from YourMechanic come to your home to diagnose and repair your charging system.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. How can you tell if your alternator is working properly?

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: Steering Column locked tight

My first instinct would be to suspect the shift interlock system. This system should only lock the wheel when the key is off. It does use a relay, actuator and signals from the PCM (powertrain control module) and the shift...

Q: Water pump in 96 Cadillac is over tightened, is the only hope to replace the water pump housing?

The only possible alternative to gain access might be to raise or lower the entire engine and transmission assembly. This would add a large amount or labor time and cost to the repair as engine and transmission mounts would have...

Q: My car will not start - Chrysler Town & Country

Hello. When the engine will not turn over, the issue is typically the starter. The clicking sound you are hearing is also another sign that the starter has failed. This is the sound of the starter motor attempting to insert...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.