Johnson City Auto Repair

Give Us a Call:(423) 928-3849

Alternator Problems and Repair


Your car’s alternator is the charging system that powers your battery and helps control all things electrical. So, for alternator problems and repair, come to Ponder Auto Repair in Johnson City. Our technicians are certified by the National Institute for Automotive Service Excellence (ASE), and we’re the only shop in Johnson City to have earned the ASE Blue Seal of Excellence.

Your vehicle uses a lot of electrical power. You’ve got lights, radio, CD players, and windshield wipers just to start. If the car’s battery was the only source of power, it would be depleted pretty quickly. That’s why your car has an alternator. Its job is to keep the car’s battery fully charged.

A recent My Auto Repair Advice article explains how the alternator maintains the battery. The engine drive belt, called the serpentine belt, sends engine power to the alternator. Now the alternator uses this power to generate electricity and send it to the battery. This keeps it fully charged and your car running. So, if your alternator isn’t working, neither is your battery. If you have alternator problems, our technicians will inspect the drive belt as part of our diagnostics.

If you are having alternator problems, your car won’t start, the serpentine belt squeals, your battery dies, or the battery light goes on. But these warning signs can also be signs of other problems, so you need to bring it to Ponder Auto Repair because we have the right diagnostic tools to find out if it is an alternator problem or something else.

We will use a digital volt-ohmmeter or DVOM (aka voltmeter), to measure how much voltage your alternator is putting out. This will allow us to pinpoint if you are having an alternator problem.

Your engine will need to be turned off. Using the voltmeter (set to DC volts) we will put the red lead on the positive side of the battery and the black lead on the negative post of the battery. We want the voltmeter to read above 12.65 volts because that means you have a fully charged battery. If it doesn’t then we need to look at the battery or the alternator as the culprit for causing problems.

Next, we will remove the leads from the battery and try and start your car. We will put the leads back on, avoiding getting them caught in the serpentine belt. With the engine on we will look at the voltage. It should be around the 13.5-14.5-volt range. If it is in this range, then it’s probably not the alternator that’s causing the problem. Alternators can be tricky though and only work sometimes. But if we think it’s not the alternator, then it is probably the battery that is faulty and we will test it to make sure.

But not all vehicles work the same. We have the diagnostic and repair information that is specific to your vehicle. To fix your alternator our expert repair technicians will disconnect your battery, remove the serpentine belt, unbolt the alternator and remove the wiring connectors.

To keep your battery fully charged and your car’s electrical components working, you need your alternator to be functioning correctly. If you have alternator problems and repair needs, come to Ponder Auto Repair in Johnson City. Our expert technicians will make sure everything is working so you don’t have to worry.


Auto Repair
Ponder Auto Repair is committed to ensuring effective communication and digital accessibility to all users. We are continually improving the user experience for everyone, and apply the relevant accessibility standards to achieve these goals. We welcome your feedback. Please call Ponder Auto Repair (423) 928-3849 if you have any issues in accessing any area of our website.