Car Stalling: Is It My Alternator Or Battery?

There’s nothing as frustrating as having your day turned upside down due to frequent car stalling. I’m not sure about you, but my day doesn’t have time to find an alternative mode of transportation. If you are currently dealing with car stalling issues, keep reading for more information on your vehicle’s electrical system to determine if the alternator or car battery needs service or replacement.

Identify The Problem: Electrical System

First things first – We must correctly identify the problem before determining which component is most likely at fault. Electrical system problems in your car can manifest in several ways. The good news is, there are usually warning signs – if we know to look for them. For instance, all the following symptoms can indicate there is an issue with your car’s electrical system:

• Dim, too bright, or flickering headlights
• Slow-moving or stuck automatic windows and sunroofs
• Hard starts
• Dashboard warning lights
• Car stalls while driving or idling
• Loose belts
• Whining or growling noise under the hood
• Burning electrical smell

A faulty alternator will ruin a good battery if you don’t address it quickly. Car batteries can only recharge so many times before they lose their ability to hold a charge. An older car battery constantly drained by a dying alternator will have a shorter life span.

How A Car Alternator Works

The alternator works with the car battery to generate energy for the electrical components of a vehicle, like the lights and instrument panel. Brackets hold the alternator to the front of the engine. The crankshaft drives the alternator, which converts the pistons’ up-and-down movement into a circular motion. Most modern cars utilize a serpentine belt that powers all the components that rely on crankshaft energy.

An alternator is named from the term ‘alternating current’ (AC), which is what it produces through electromagnetism. The alternator contains semiconductors (or diodes) that convert the AC (alternating current) it makes to DC (direct current) to send to the car battery. The electricity produced by the alternator is stored in the car battery and used by the vehicle’s electric and auxiliary systems.

How A Car Battery Works

A standard 12-volt lead acid car battery works through a chemical reaction between the six plates and the acid solution inside the case. This reaction causes electrons to flow from negative to positive plates, creating electrical energy. Car batteries produce DC voltage, which supplies power via the positive battery cable to the starter motor to start the engine. It also acts as a capacitor which evens out electrical currents to protect your vehicle’s extensive onboard electronics.

Car Stalling: Troubleshooting

Okay, now that we know more about how your alternator and car battery work together, let’s review the possible causes for your car stalling.

Failing Alternator

Generally speaking, the alternator is a maintenance-free component; with some cars, it can last 10-15 years without any repairs. Listen for whining or growling sounds and burning smells, as these signs indicate alternator issues. Your car may still run briefly on battery power if the alternator fails. However, car stalling occurs as soon as the battery charge runs out.

Dying Car Battery

Suppose the starter motor slowly cranks the engine or the dashboard Battery/Charging warning light turns on. In that case, you may have a battery problem. In older model cars, dim incandescent headlights, especially when idling, indicate a weakened car battery. To help prevent an unexpected dead car battery, inspect it at every oil change.

Battery Cables

Check that the cable connections are free of corrosion, fastened tightly, and the mounting bracket is secure.

Loose or Damaged Serpentine Belt

The serpentine belt engages engine components such as the alternator, water pump, and air conditioner compressor. A loose or damaged serpentine belt not fully engaged with the alternator can overheat the engine or create power issues.

Wiring or Fuses

On some occasions, the alternator and car battery may be operating fine, but due to broken or disconnected wiring or even a blown fuse, the current they produce is lost along the way.

Dashboard Warning Lights

Most modern vehicles have a vast array of dashboard warning lights. If you have electrical system problems, the battery-shaped icon or ALT may illuminate. Even if you have no other symptoms, always bring your car in for a quick trouble code diagnostic when your dashboard warning lights are on. After all, the manufacturer put the warning lights there to warn drivers of problems before they turn catastrophic.

Routine Auto Maintenance in Kirkland, WA

Auto manufacturers recommend specific routine maintenance intervals for every car they make. Following these recommendations can keep your vehicle in tip-top shape and avoid costly repairs due to incomplete or overlong maintenance.  

• Often, an alternator fails prematurely when the protective engine under-shield is damaged or missing. This happens because water, oil, and coolant from the road or engine compartment get inside the alternator and cause it to wear faster. If your engine under-shield is damaged, replace it to keep the engine compartment dry and debris-free.
• Car battery maintenance is also vital to prolonging battery life. Gone are the days when car batteries were inexpensive and lasted decades. Modern vehicles come equipped with way more electronic devices and systems than ever, creating more draw on the car battery. 

Your owner’s manual is a valuable resource for routine auto maintenance schedules and troubleshooting tips. If you require more information, consult a qualified technician at your local auto service center.

Electrical System Diagnostic Service 

At Fisher’s Auto Service, we understand cars and the people who drive them. Since 1979, our team has been providing exceptional and reasonably priced service. Our certified technicians use advanced technology to diagnose your vehicle’s electrical system issues, from your alternator to your car battery and everything in between.

Schedule Your Car Stalling Service 

Call us at (425)441-3626 or visit us online to schedule your electrical system service today! Our technicians will resolve your car stalling issue and safely get you back on the road.