Q: Is this my battery or alternator?

asked by on November 27, 2016

I pulled into my parking lot and my car power just turned off and I couldn't press my brakes or park my car without pulling my emergency brakes.

My car has 158000 miles.
My car has an automatic transmission.

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 the engine turns the alternator. The voltage regulator is a unit that regulates the charging of the battery by the alternator and maintaining a certain amperage while the engine runs. When the alternator is not working properly, this may result in the battery quickly losing charge and the car losing all power as you have described. I would recommend having an expert from YourMechanic come to your location 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

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

What does the Replace Battery in Remote Key message mean?

The Replace Battery in Remote Key message appears on your driver information center (DIC) when the batter in the remote keyless entry (RKE) transmitter needs to be replaced. When a new battery is added to the RKE, the DIC alert...

How long does it take to install an alternator in a 1982 Toyota Tercel

Hello, thank you for writing in. An alternator replacement typically takes around an hour. This is dependent of course on the condition of the old unit and how difficult it is to remove. The tools needed are fairly basic. The...

Car not recognizing Park setting

The vehicle is equipped with a park/neutral switch which is the device used for the vehicle to differentiate between park or neutral for starting the car or releasing the key. A fault here may be causing your concerns. I recommend...

Related articles

All About Car Battery Chargers
Everyone Everyone has experienced a dead car battery from time to time. It’s common occurance, especially in winter, when batteries have to work even harder to get you to where you want to go. Fortunately, there’s a solution. A portable...
Can a Car Battery Overheat in Hot Weather?
Hot weather can cause battery fluid to evaporate and make it hard to start your car. Battery overcharging decreases the lifespan of your battery.
How the Alternator Works in Your Car
Your Your car alternator, at its most basic, is what works along with your battery and the rest of your charging system to keep your car running. When you start your car, you’re running on battery power. Then the battery...